1.
Herb
–
In general use, herbs are any plants used for food, flavoring, medicine, or fragrances for their savory or aromatic properties. Culinary use typically distinguishes herbs from spices, Herbs refers to the leafy green or flowering parts of a plant, while spices are produced from other parts of the plant, including seeds, berries, bark, roots and fruits. In botanical English, the herb is also used as a synonym of herbaceous plant. Herbs have a variety of uses including culinary, medicinal, and in some cases, general usage of the term herb differs between culinary herbs and medicinal herbs. In medicinal or spiritual use any of the parts of the plant might be considered herbs, including leaves, roots, flowers, seeds, root bark, inner bark, resin and pericarp. The word herb is pronounced /ˈhɜːrb/ in the UK, but /ˈɜːrb/ is common among North American speakers, as far back as 5000 BCE, Sumerians used herbs in medicine. Ancient Egyptians used fennel, coriander and thyme around 1555 BCE, in ancient Greece, in 162 CE, a physician by the name of Galen was known for concocting complicated herbal remedies that contained up to 100 ingredients. Culinary herbs are distinguished from vegetables in that, like spices, they are used in small amounts, Herbs can be perennials such as thyme or lavender, biennials such as parsley, or annuals like basil. Perennial herbs can be such as rosemary, Rosmarinus officinalis, or trees such as bay laurel, Laurus nobilis – this contrasts with botanical herbs. Some plants are used as herbs and spices, such as dill weed and dill seed or coriander leaves and seeds. Also, there are some such as those in the mint family that are used for both culinary and medicinal purposes. Some plants contain phytochemicals that have effects on the body, there may be some effects when consumed in the small levels that typify culinary spicing, and some herbs are toxic in larger quantities. For instance, some types of herbal extract, such as the extract of St. Johns-wort or of kava can be used for purposes to relieve depression. However, large amounts of these herbs may lead to toxic overload that may involve complications, some of a serious nature, Herbs have long been used as the basis of traditional Chinese herbal medicine, with usage dating as far back as the first century CE and far before. In India, the Ayurveda medicinal system is based on herbs, medicinal use of herbs in Western cultures has its roots in the Hippocratic elemental healing system, based on a quaternary elemental healing metaphor. Famous herbalist of the Western tradition include Avicenna, Galen, Paracelsus, Culpepper, the indigenous peoples of Australia developed herbal medicine based on plants that were readily available to them. The isolation of the people meant the remedies developed were for far less serious diseases. Herbs such as mint, wattle and eucalyptus were used for coughs, diarrhea, fever
Herb
–
Basil and
green onions, common culinary herbs
Herb
–
A bundle of
thyme
2.
Trientalis latifolia
–
Trientalis latifolia is a species in the genus Trientalis in the family Primulaceae. It is also known as starflower, chickweed-wintergreen, or Pacific starflower, height and spread, Low-growing, creeping perennial reaching. Leaves,5 to 7 whorled, lanceolate, entire leaves distributed levelly in a single group, flowers, White or pink flowers are borne in April or May. Calyx is 5- to 9-parted and persistent, corolla is also 5- to 9-parted, rotate, with a very short tube and elliptic-lanceolate segments. Stamens occur in the number as the corolla lobes and are positioned opposite them. 1-3 Peduncles, 1-flowered, filiform, and ebracteate, propagate in spring by division or seeds, for which no treatment is needed, but only fresh seeds should be used. Occurs on moist, shaded slopes in deep, light soil rich in organic matter, canada, Occurs in British Columbia, Alberta, and Yukon. United States of America, Occurs throughout Washington, Idaho, Oregon, Trientalis is derived from the Latin triens, and is an allusion to the height of the plant, which is one third of a foot, or four inches high. Latifolia is derived from two words in Latin, latus, meaning broad or wide, and folius, meaning leaved, media related to Trientalis latifolia at Wikimedia Commons Jepson Manual Online Trientalis latifolia Hook
Trientalis latifolia
–
Trientalis latifolia
3.
Botany
–
Botany, also called plant science, plant biology or phytology, is the science of plant life and a branch of biology. A botanist or plant scientist is a scientist who specialises in this field, the term botany comes from the Ancient Greek word βοτάνη meaning pasture, grass, or fodder, βοτάνη is in turn derived from βόσκειν, to feed or to graze. Nowadays, botanists study approximately 410,000 species of plants of which some 391,000 species are vascular plants. Medieval physic gardens, often attached to monasteries, contained plants of medical importance and they were forerunners of the first botanical gardens attached to universities, founded from the 1540s onwards. One of the earliest was the Padua botanical garden and these gardens facilitated the academic study of plants. Efforts to catalogue and describe their collections were the beginnings of plant taxonomy, in the last two decades of the 20th century, botanists exploited the techniques of molecular genetic analysis, including genomics and proteomics and DNA sequences to classify plants more accurately. Modern botany is a broad, multidisciplinary subject with inputs from most other areas of science, dominant themes in 21st century plant science are molecular genetics and epigenetics, which are the mechanisms and control of gene expression during differentiation of plant cells and tissues. Botany originated as herbalism, the study and use of plants for their medicinal properties, many records of the Holocene period date early botanical knowledge as far back as 10,000 years ago. This early unrecorded knowledge of plants was discovered in ancient sites of human occupation within Tennessee, the early recorded history of botany includes many ancient writings and plant classifications. Examples of early works have been found in ancient texts from India dating back to before 1100 BC, in archaic Avestan writings. His major works, Enquiry into Plants and On the Causes of Plants, constitute the most important contributions to science until the Middle Ages. De Materia Medica was widely read for more than 1,500 years, important contributions from the medieval Muslim world include Ibn Wahshiyyas Nabatean Agriculture, Abū Ḥanīfa Dīnawarīs the Book of Plants, and Ibn Bassals The Classification of Soils. In the early 13th century, Abu al-Abbas al-Nabati, and Ibn al-Baitar wrote on botany in a systematic and scientific manner and these gardens continued the practical value of earlier physic gardens, often associated with monasteries, in which plants were cultivated for medical use. They supported the growth of botany as an academic subject, lectures were given about the plants grown in the gardens and their medical uses demonstrated. Botanical gardens came much later to northern Europe, the first in England was the University of Oxford Botanic Garden in 1621, throughout this period, botany remained firmly subordinate to medicine. German physician Leonhart Fuchs was one of the three German fathers of botany, along with theologian Otto Brunfels and physician Hieronymus Bock, Fuchs and Brunfels broke away from the tradition of copying earlier works to make original observations of their own. Bock created his own system of plant classification, physician Valerius Cordus authored a botanically and pharmacologically important herbal Historia Plantarum in 1544 and a pharmacopoeia of lasting importance, the Dispensatorium in 1546. Naturalist Conrad von Gesner and herbalist John Gerard published herbals covering the medicinal uses of plants, naturalist Ulisse Aldrovandi was considered the father of natural history, which included the study of plants
Botany
–
The fruit of
Myristica fragrans, a species native to
Indonesia, is the source of two valuable spices, the red aril (
mace) enclosing the dark brown
nutmeg.
Botany
–
The
Linnaean Garden of Linnaeus' residence in Uppsala, Sweden, was planted according to his Systema sexuale.
Botany
–
Micropropagation of transgenic plants
Botany
–
Biologist and statistician Ronald Fisher
4.
Plant
–
Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. The term is generally limited to the green plants, which form an unranked clade Viridiplantae. This includes the plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants have cell walls containing cellulose and obtain most of their energy from sunlight via photosynthesis by primary chloroplasts and their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic and have lost the ability to produce amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although reproduction is also common. There are about 300–315 thousand species of plants, of which the great majority, green plants provide most of the worlds molecular oxygen and are the basis of most of Earths ecologies, especially on land. Plants that produce grains, fruits and vegetables form humankinds basic foodstuffs, Plants play many roles in culture. They are used as ornaments and, until recently and in variety, they have served as the source of most medicines. The scientific study of plants is known as botany, a branch of biology, Plants are one of the two groups into which all living things were traditionally divided, the other is animals. The division goes back at least as far as Aristotle, who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus created the basis of the system of scientific classification. Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, however, these organisms are still often considered plants, particularly in popular contexts. When the name Plantae or plant is applied to a group of organisms or taxon. The evolutionary history of plants is not yet settled. Those which have been called plants are in bold, the way in which the groups of green algae are combined and named varies considerably between authors. Algae comprise several different groups of organisms which produce energy through photosynthesis, most conspicuous among the algae are the seaweeds, multicellular algae that may roughly resemble land plants, but are classified among the brown, red and green algae. Each of these groups also includes various microscopic and single-celled organisms
Plant
–
Green algae from
Ernst Haeckel 's
Kunstformen der Natur, 1904.
Plant
–
Had'n
Plant
–
Dicksonia antarctica, a species of
tree fern
Plant
–
A petrified log in
Petrified Forest National Park.
5.
Wood
–
Wood is a porous and fibrous structural tissue found in the stems and roots of trees, and other woody plants. It is a material, a natural composite of cellulose fibers which are strong in tension embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, in a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots, Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber. In 2005, the stock of forests worldwide was about 434 billion cubic meters. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy, in 1991 approximately 3.5 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction, a 2011 discovery in the Canadian province of New Brunswick discovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in species by dendrochronology to make inferences about when a wooden object was created. People have used wood for millennia for many purposes, primarily as a fuel or as a material for making houses, tools, weapons, furniture, packaging, artworks. Constructions using wood date back ten thousand years, buildings like the European Neolithic long house were made primarily of wood. Recent use of wood has changed by the addition of steel. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the climate at that time. This process is known as growth, it is the result of cell division in the vascular cambium, a lateral meristem. These cells then go on to form thickened secondary cell walls, composed mainly of cellulose, hemicellulose, if the distinctiveness between seasons is annual, these growth rings are referred to as annual rings. Where there is little seasonal difference growth rings are likely to be indistinct or absent, if the bark of the tree has been removed in a particular area, the rings will likely be deformed as the plant overgrows the scar. It is usually lighter in color than that near the portion of the ring. The outer portion formed later in the season is known as the latewood or summerwood. However, there are differences, depending on the kind of wood
Wood
–
Diagram of
secondary growth in a
tree showing idealised vertical and horizontal sections. A new layer of wood is added in each growing season, thickening the stem, existing branches and
roots, to form a
growth ring.
Wood
Wood
–
A knot on a tree at the
Garden of the Gods public park in
Colorado Springs, Colorado (October 2006)
Wood
–
Wood knot in vertical section
6.
Annual plant
–
An annual plant is a plant that completes its life cycle, from germination to the production of seed, within one year, and then dies. Summer annuals germinate during spring or early summer and mature by autumn of the same year, winter annuals germinate during the autumn and mature during the spring or summer of the following calendar year. One seed-to-seed life cycle for an annual can occur in as little as a month in some species, oilseed rapa can go from seed-to-seed in about five weeks under a bank of fluorescent lamps. This style of growing is used in classrooms for education. Many desert annuals are therophytes, because their life cycle is only weeks. In cultivation, many plants are, or are grown as, annuals. Some perennials and biennials are grown in gardens as annuals for convenience, carrot, celery and parsley are true biennials that are usually grown as annual crops for their edible roots, petioles and leaves, respectively. Tomato, sweet potato and bell pepper are tender perennials usually grown as annuals, ornamental perennials commonly grown as annuals are impatiens, wax begonia, snapdragon, Pelargonium, coleus and petunia. Examples of true annuals include corn, wheat, rice, lettuce, peas, watermelon, beans, zinnia, summer annuals sprout, flower, produce seed, and die, during the warmer months of the year. The lawn weed crabgrass is a summer annual, winter annuals germinate in autumn or winter, live through the winter, then bloom in winter or spring. The plants grow and bloom during the season when most other plants are dormant or other annuals are in seed form waiting for warmer weather to germinate. Winter annuals die after flowering and setting seed, the seeds germinate in the autumn or winter when the soil temperature is cool. Winter annuals typically grow low to the ground, where they are sheltered from the coldest nights by snow cover. Some common winter annuals include henbit, deadnettle, chickweed, ironically, the property that they prevent the soil from drying out can also be problematic for commercial agriculture. In 2008, it was discovered that the inactivation of only two genes in one species of annual plant leads to the conversion into a perennial plant, researchers deactivated the SOC1 and FUL genes in Arabidopsis thaliana, which control flowering time. This switch established phenotypes common in plants, such as wood formation
Annual plant
–
Peas are an annual plant.
7.
Biennial plant
–
A biennial plant is a flowering plant that takes two years to complete its biological lifecycle. In the first year, the plant grows leaves, stems, usually the stem remains very short and the leaves are low to the ground, forming a rosette. Many biennials require a treatment, or vernalization, before they will flower. During the next spring or summer, the stem of the biennial plant elongates greatly and this typically makes biennial vegetables such as spinach, fennel and lettuce unusable as food. The plant then flowers, producing fruits and seeds before it finally dies, there are far fewer biennials than either perennial plants or annual plants. Under extreme climatic conditions, a plant may complete its life cycle rapidly. This is quite common in vegetable or flower seedlings that were vernalized before they were planted in the ground and this behavior leads to many normally biennial plants being treated as annuals in some areas. From a gardeners perspective, a status as annual, biennial. Biennials grown for flowers, fruits, or seeds need to be grown for two years, biennials that are grown for edible leaves or roots are grown for just one year. Plant breeders have produced annual cultivars of several biennials that will flower the first year from seed, for example, foxglove and stock
Biennial plant
–
Parsley is a common example of a biennial plant.
Biennial plant
–
The Sweet William Dwarf plant is a biennial plant
8.
Perennial plant
–
A perennial plant or simply perennial is a plant that lives for more than two years. The term is used to differentiate a plant from shorter-lived annuals and biennials. The term is widely used to distinguish plants with little or no woody growth from trees and shrubs. Tomato vines, for example, live several years in their natural habitat but are grown as annuals in temperate regions because they dont survive the winter. There is also a class of evergreen, or non-herbaceous, perennials, an intermediate class of plants is known as subshrubs, which retain a vestigial woody structure in winter, e. g. Penstemon. The local climate may dictate whether plants are treated as shrubs or perennials, for instance, many varieties of Fuchsia are shrubs in warm regions, but in colder temperate climates may be cut to the ground every year as a result of winter frosts. The symbol for a plant, based on Species Plantarum by Linnaeus, is. Perennial plants can be short-lived or they can be long-lived, as are some plants like trees. They include an assortment of plant groups from ferns and liverworts to the highly diverse flowering plants like orchids. Plants that flower and fruit only once and then die are termed monocarpic or semelparous, however, most perennials are polycarpic, flowering over many seasons in their lifetime. Perennials typically grow structures that allow them to adapt to living one year to the next through a form of vegetative reproduction rather than seeding. These structures include bulbs, tubers, woody crowns, rhizomes plus others and they might have specialized stems or crowns that allow them to survive periods of dormancy over cold or dry seasons during the year. Many perennials have developed specialized features that allow them to extreme climatic. Some have adapted to hot and dry conditions or cold temperatures. Those plants tend to invest a lot of resource into their adaptations and often do not flower, Many perennials produce relatively large seeds, which can have an advantage, with larger seedlings produced after germination that can better compete with other plants. Some annuals produce many seeds per plant in one season, while some perennials are not under the same pressure to produce large numbers of seeds. In warmer and more favorable climates, perennials grow continuously, in seasonal climates, their growth is limited to the growing season. In some species, perennials retain their foliage all year round, other plants are deciduous perennials, for example, in temperate regions a perennial plant may grow and bloom during the warm part of the year, with the foliage dying back in the winter
Perennial plant
–
Common chicory,
Cichorium intybus, is a herbaceous perennial plant
Perennial plant
–
Dahlia plants are perennial.
Perennial plant
–
Switchgrass is a deep-rooted perennial. These roots are more than 3 meters long.
Perennial plant
9.
Plant stem
–
A stem is one of two main structural axes of a vascular plant, the other being the root. The stem is divided into nodes and internodes, The nodes hold one or more leaves. Adventitious roots may also be produced from the nodes, the internodes distance one node from another. The term shoots is often confused with stems, shoots generally refers to new plant growth including both stems and other structures like leaves or flowers. In most plants stems are located above the surface but some plants have underground stems. Stems have four main functions which are, Support for and the elevation of leaves, flowers, the stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits. Transport of fluids between the roots and the shoots in the xylem and phloem Storage of nutrients Production of new living tissue, the normal lifespan of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue, Stems are often specialized for storage, asexual reproduction, protection or photosynthesis, including the following, Acaulescent – used to describe stems in plants that appear to be stemless. Actually these stems are just extremely short, the leaves appearing to rise out of the ground. Arborescent – tree like with woody stems normally with a single trunk, branched – aerial stems are described as being branched or unbranched Bud – an embryonic shoot with immature stem tip. Bulb – a short underground stem with fleshy storage leaves attached, e. g. onion, daffodil. Bulbs often function in reproduction by splitting to form new bulbs or producing small new bulbs termed bulblets, bulbs are a combination of stem and leaves so may better be considered as leaves because the leaves make up the greater part. Caespitose – when stems grow in a mass or clump or in low growing mats. Cladode – a flattened stem that appears more-or-less leaf like and is specialized for photosynthesis, climbing – stems that cling or wrap around other plants or structures. Corm – a short enlarged underground, storage stem, e. g. taro, decumbent – stems that lie flat on the ground and turn upwards at the ends. Fruticose – stems that grow shrublike with woody like habit, herbaceous – non woody, they die at the end of the growing season. Pedicel – stems that serve as the stalk of a flower in an inflorescence or infrutescence. Peduncle – a stem that supports an inflorescence Prickle – a sharpened extension of the outer layers
Plant stem
–
Stem showing internode and nodes plus leaf
petioles
Plant stem
–
This above-ground stem of
Polygonatum has lost its leaves, but is producing
adventitious roots from the nodes.
Plant stem
–
Flax stem cross-section, showing locations of underlying tissues. Ep =
epidermis; C =
cortex; BF =
bast fibres; P =
phloem; X =
xylem; Pi =
pith
Plant stem
–
Stems of two
Roystonea regia palms showing characteristic bulge, leaf scars and fibrous roots,
Kolkata, India
10.
Root
–
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. Roots can also be aerial or aerating, that is growing up above the ground or especially above water, furthermore, a stem normally occurring below ground is not exceptional either. Therefore, the root is best defined as the non-leaf, non-nodes bearing parts of the plants body, however, important internal structural differences between stems and roots exist. The fossil record of roots – or rather, infilled voids where roots rotted after death – spans back to the late Silurian and their identification is difficult, because casts and molds of roots are so similar in appearance to animal burrows. They can be discriminated using a range of features, the first root that comes from a plant is called the radicle. In response to the concentration of nutrients, roots also synthesise cytokinin, Roots often function in storage of food and nutrients. The roots of most vascular plant species enter into symbiosis with fungi to form mycorrhizae. In its simplest form, the root architecture refers to the spatial configuration of a plant’s root system. This system can be complex and is dependent upon multiple factors such as the species of the plant itself, the composition of the soil. The configuration of root systems serves to support the plant, compete with other plants. Roots grow to specific conditions, which, if changed, can impede a plants growth. For example, a system that has developed in dry soil may not be as efficient in flooded soil, yet plants are able to adapt to other changes in the environment. Root architecture plays the important role of providing a supply of nutrients and water as well as anchorage. The main terms used to classify the architecture of a system are, Branch magnitude. Root angle, the angle of a lateral root’s base around the parent root’s circumference, the angle of a lateral root from its parent root. Link radius, the diameter of a root, all components of the root architecture are regulated through a complex interaction between genetic responses and responses due to environmental stimuli. These developmental stimuli are categorised as intrinsic, the genetic and nutritional influences, or extrinsic, the main hormones and respective pathways responsible for root architecture development include, Auxin – Auxin promotes root initiation, root emergence and primary root elongation. Cytokinins – Cytokinins regulate root apical meristem size and promote lateral root elongation, gibberellins – Together with ethylene they promote crown primordia growth and elongation
Root
–
Primary and secondary roots in a cotton plant
Root
–
Large, mature tree roots above the soil
Root
–
The cross-section of a
barley root
Root
–
Roots of trees
11.
Bulb
–
In botany, a bulb is structurally a short stem with fleshy leaves or leaf bases that function as food storage organs during dormancy. A bulbs leaf bases, also known as scales, generally do not support leaves, at the center of the bulb is a vegetative growing point or an unexpanded flowering shoot. The base is formed by a stem, and plant growth occurs from this basal plate. Roots emerge from the underside of the base, and new stems, tunicate bulbs have dry, membranous outer scales that protect the continuous lamina of fleshy scales. Species in the genera Allium, Hippeastrum, Narcissus, and Tulipa all have tunicate bulbs, non-tunicate bulbs, such as Lilium and Fritillaria species, lack the protective tunic and have looser scales. The technical term geophyte encompasses plants that form underground organs, including bulbs as well as tubers. Some epiphytic orchids form above-ground storage organs called pseudobulbs, that superficially resemble bulbs, nearly all plants that form true bulbs are monocotyledons, and include, Amaryllis, Crinum, Hippeastrum, Narcissus, and several other members of the amaryllis family Amaryllidaceae. This includes onion, garlic, and other alliums, members of the Amaryllid subfamily Allioideae, lily, tulip, and many other members of the lily family Liliaceae. Two groups of Iris species, family Iridaceae, subgenus Xiphium, oxalis, in the family Oxalidaceae, is the only dicotyledon genus that produces true bulbs. Bulbous plant species cycle through vegetative and reproductive stages, the bulb grows to flowering size during the vegetative stage. Certain environmental conditions are needed to trigger the transition from one stage to the next, bulbs dug up before the foliage period is completed will not bloom the following year but then should flower normally in subsequent years. After the foliage period is completed, bulbs may be dug up for replanting elsewhere, any surface moisture should be dried, then the bulbs may be stored up to about 4 months for a fall planting. Storing them much longer than that may cause the bulbs to dry out inside, a bulbil is a small bulb, and may also be called a bulblet, bulbet, or bulbel. Small bulbs can develop or propagate a large bulb, if one or several moderate-sized bulbs form to replace the original bulb, they are called renewal bulbs. Increase bulbs are small bulbs that develop either on each of the leaves inside a bulb, some lilies, such as the tiger lily Lilium lancifolium, form small bulbs, called bulbils, in their leaf axils. Several members of the family, Alliaceae, including Allium sativum, form bulbils in their flower heads, sometimes as the flowers fade. The so-called tree onion forms small onions which are enough for pickling. Some ferns, such as Hen and Chicken Fern produce new plants at the tips of the fronds pinnae, coccoris, Patricia The Curious History of the Bulb Vase
Bulb
–
Shallot bulbs
Bulb
–
Hippeastrum (amaryllis) bulb
Bulb
–
Cross section of onion bulb
Bulb
–
Bulbils form in the leaf axils of
Lilium lancifolium
12.
Corm
–
The word cormous is used to describe plants growing from corms, in analogy to the use of the terms tuberous and bulbous to describe plants growing from tubers and bulbs. A corm consists of one or more internodes with at least one growing point, the tunic of a corm is formed from dead petiole sheaths, remnants of leaves produced in previous years. They act as a covering, protecting the corm from insects, digging animals, flooding, and water loss. The tunics of some species are thin, dry, and papery, at least in plants, however, in some families, such as Iridaceae. For example, some of the species of Watsonia accumulate thick, rot-resistant tunics over a period of some years. Other species, such as many in the genus Lapeirousia, have tunics of hard, internally a typical corm mostly consists of parenchyma cells rich in starch, above a circular basal node from which roots grow. Long-lived cormous plants vary in their long-term development, some regularly replace their older corms with a stack of younger corms, increased more or less seasonally. By splitting such a stack before the older corm generations wither too badly, other species seldom do anything of that kind, their corms simply grow larger in most seasons. Yet others split when multiple buds or stolons on a large corm sprout independently, corms can be dug up and used to propagate or redistribute the plant. Plants with corms generally can be propagated by cutting the corms into sections, suitably treated, each section with at least one bud usually can generate a new corm. Corms are sometimes confused with true bulbs, they are similar in appearance to bulbs externally. Corms are stems that are structured with solid tissues, which distinguishes them from bulbs. As a result, when a corm is cut in half it is solid, corms are structurally plant stems, with nodes and internodes with buds and produce adventitious roots. On the top of the corm, one or a few grow into shoots that produce normal leaves. Corms can form many small cormlets called cormels, from the areas of the new growing corms. They are used to propagate corm-forming plants, corms of a number of species of plants are replaced every year by the plant with growth of a new corm, this process starts after the shoot has developed fully expanded leaves. The new corm forms at the base just above the old corm. As the new corm is growing, short stolons are produced that end with the growing small cormels
Corm
–
Taro corms for sale in a
Réunion market
Corm
–
Crocosmia corm with the tunic partly stripped to show its origin at the nodes on the corm
cortex
Corm
–
Crocosmia corm anatomy, showing tunic,
cortex of storage tissue, central medulla, and emergence of a new corm from a bud near the top.
Corm
–
Crocosmia corm with
stolons emerging through the tunic. The stolons originate at the axillary buds of the corm scales, and generally produce new corms at their tips
13.
Stolon
–
In biology, stolons, also known as runners, are horizontal connections between organisms. They may be part of the organism, or of its skeleton, typically, in botany, stolons are stems which grow at the soil surface or just below ground that form adventitious roots at the nodes, and new plants from the buds. Rhizomes, in contrast, are root-like stems that may either grow horizontally at the surface or in other orientations underground. Thus, not all horizontal stems are called stolons, plants with stolons are called stoloniferous. A stolon is a plant propagation strategy and the complex of individuals formed by a plant and all its clones produced from stolons form a single genetic individual. Stolons may or may not have long internodes, the leaves along the stolon are usually very small, but in a few cases such as Stachys sylvatica are normal in size. Stolons arise from the base of the plant, the nodes of the stolons produce roots, often all around the node and hormones produced by the roots cause the stolon to initiate shoots with normal leaves. A number of plants have soil-level or above-ground rhizomes, including Iris species and he recognized stolons as axillary, subterranean branches that do not bear green leaves but only membranaceous, scale-like ones. In some Cyperus species the stolons end with the growth of tubers, some species of crawling plants can also sprout adventitious roots, but are not considered stoloniferous, a stolon is sprouted from an existing stem and can produce a full individual. Examples of plants that extend through stolons include some species from the genera Argentina, Cynodon, Fragaria, other plants with stolons below the soil surface include many grasses, Ajuga, Mentha, and Stachys. Lily-of-the-valley has rhizomes that grow stolon-like stems called stoloniferous rhizomes or leptomorph rhizomes, a number of plants have stoloniferous rhizomes including Asters. These stolon-like rhizomes are long and thin, with long internodes and indeterminate growth with lateral buds at the node, in potatoes, the stolons start to grow within 10 days of plants emerging above ground, with tubers usually beginning to form on the end of the stolons. The tubers are modified stolons that hold food reserves, with a few buds grow into stems. Since it is not a rhizome it does not generate roots, see also BBCH-scale Hydrilla use stolons that produce tubers to spread themselves and to survive dry periods in aquatic habitats. Erythronium, commonly called Trout Lily, have white stolons growing from the bulb, most run horizontally, either underground or along the surface of the ground under leaf litter. A number of species produce stolons, such as Erythronium propullans. Flowering plants often produce no stolons, convolvulus arvensis is a weed species in agriculture that spreads by under ground stolons that produce rhizomes. In studies on grass species, with plants that produce stolons or rhizomes, in mycology, a stolon is defined as an occasionally septate hypha, which connects sporangiophores together
Stolon
–
Pingao (Ficinia spiralis) spreads by forming stolons in the sand.
Stolon
–
Common Silverweed (
Argentina anserina) picture showing red stolons.
Stolon
–
These stolons from the
corm of a
Crocosmia are stems that emerged from axillary buds at the nodes of the
tunic leaves.
Stolon
–
'Lipstick' hybrid strawberry (Comarum palustre × Fragaria × ananassa) along stolons.
14.
Rhizome
–
In botany and dendrology, a rhizome is a modified subterranean stem of a plant that is usually found underground, often sending out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks and rootstocks, Rhizomes develop from axillary buds and are diageotropic or grow perpendicular to the force of gravity. The rhizome also retains the ability to new shoots to grow upwards. If a rhizome is separated into pieces, each piece may be able to rise to a new plant. The plant uses the rhizome to store starches, proteins, and these nutrients become useful for the plant when new shoots must be formed or when the plant dies back for the winter. This is a known as vegetative reproduction and is used by farmers and gardeners to propagate certain plants. This also allows for lateral spread of grasses like bamboo and bunch grasses, examples of plants that are propagated this way include hops, asparagus, ginger, irises, Lily of the Valley, cannas, and sympodial orchids. Some rhizomes which are used directly in cooking include ginger, turmeric, galangal, stored rhizomes are subject to bacterial and fungal infections, making them unsuitable for replanting and greatly diminishing stocks. However, rhizomes can also be produced artificially from tissue cultures, the ability to easily grow rhizomes from tissue cultures leads to better stocks for replanting and greater yields. The plant hormones ethylene and jasmonic acid have found to help induce and regulate the growth of rhizomes. Ethylene that was applied externally was found to affect internal ethylene levels, knowledge of how to use these hormones to induce rhizome growth could help farmers and biologists producing plants grown from rhizomes more easily cultivate and grow better plants. The poplars are an example of trees that propagate using a rhizome, the Pando colony in Utah is a famous example, which has been living for about 80,000 years. In general, rhizomes have short internodes, they send out roots from the bottom of the nodes, a stem tuber is a thickened part of a rhizome or stolon that has been enlarged for use as a storage organ. In general, a tuber is high in starch, for example, the common potato, the term tuber is often used imprecisely, and is sometimes applied to plants with rhizomes. Some plants have rhizomes that grow above ground or that lie at the surface, including some Iris species. Rhizomes generally form a layer, but in Giant Horsetails. Many rhizomes have culinary value, and some, such as zheergen, are consumed raw. Aspen Corm Mycorrhiza Media related to Rhizomes at Wikimedia Commons
Rhizome
–
Lotus rhizome
Rhizome
–
An
antique spurge plant;
Euphorbia antiquorum, sending out rhizomes
Rhizome
–
Turmeric rhizome and spice
Rhizome
–
Stolons growing from nodes in
corm of
Crocosmia.
15.
Tuber
–
Tubers are enlarged structures in some plant species used as storage organs for nutrients. They are used for the plants perennation, to energy and nutrients for regrowth during the next growing season. Stem tubers form from thickened rhizomes or stolons, common plant species with stem tubers include potato and yam. Some sources also treat modified lateral roots under the definition, these are encountered in sweet potato, cassava, the term originates from Latin tuber, meaning lump, bump, swelling. Some sources define the term tuber to mean only structures derived from stems, a stem tuber forms from thickened rhizomes or stolons. The top sides of the tuber produce shoots that grow into stems and leaves. They tend to form at the sides of the parent plant and are most often located near the soil surface, the underground stem tuber is normally a short-lived storage and regenerative organ developing from a shoot that branches off a mature plant. The offsprings or new tubers are attached to a parent tuber or form at the end of a hypogeogenous rhizome, some plants also form smaller tubers and/or tubercules which act like seeds, producing small plants that resemble seedlings. Stem tubers generally start off as enlargements of the section of a seedling. Tuberous begonia, yams, and Cyclamen are commonly grown stem tubers, mignonette vine produces aerial stem tubers on 12-to-25-foot-tall vines, the tubers fall to the ground and grow. Enlarged stolons thicken to develop into storage organs, the tuber has all the parts of a normal stem, including nodes and internodes. The nodes are the eyes and each has a leaf scar, the nodes or eyes are arranged around the tuber in a spiral fashion beginning on the end opposite the attachment point to the stolon. The terminal bud is produced at the farthest point away from the stolon attachment, internally, a tuber is filled with starch stored in enlarged parenchyma like cells. The inside of a tuber has the cell structures of any stem, including a pith, vascular zones. The tuber is produced in one growing season and used to perennate the plant, as the main shoot develops from the tuber, the base of the shoot close to the tuber produces adventitious roots and lateral buds on the shoot. The shoot also produces stolons that are long etiolated stems, the stolon elongates during long days with the presence of high auxins levels that prevent root growth off of the stolon. Before new tuber formation begins, the stolon must be a certain age, the enzyme lipoxygenase makes a hormone, jasmonic acid, which is involved in the control of potato tuber development. The stolons are easily recognized when potato plants are grown from seeds, as the plants grow, stolons are produced around the soil surface from the nodes
Tuber
–
Oca tubers
Tuber
–
Freshly dug sweet potato plants with tubers.
16.
Carrot
–
The carrot is a root vegetable, usually orange in colour, though purple, black, red, white, and yellow cultivars exist. Carrots are a form of the wild carrot, Daucus carota, native to Europe. The plant probably originated in Persia and originally cultivated for its leaves, the most commonly eaten part of the plant is the taproot, although the greens are sometimes eaten as well. The domestic carrot has been bred for its greatly enlarged, more palatable. The carrot is a plant in the umbellifer family Apiaceae. At first, it grows a rosette of leaves while building up the enlarged taproot, fast-growing cultivars mature within three months of sowing the seed, while slower-maturing cultivars are harvested four months later. The United Nations Food and Agriculture Organization reports that production of carrots and turnips for the calendar year 2013 was 37.2 million tonnes. Carrots are widely used in many cuisines, especially in the preparation of salads, in Old English, carrots were not clearly distinguished from parsnips, the two were collectively called moru or more. Various languages still use the word for carrot as they do for root. Molecular and genetic studies, along with history, support the idea that the cultivated/domesticated carrot has a single origin in Central Asia. The wild ancestors of the carrot are likely to have originated in Persia, which remains the centre of diversity for Daucus carota, when they were first cultivated, carrots were grown for their aromatic leaves and seeds rather than their roots. Carrot seeds have been found in Switzerland and Southern Germany dating back to 2000–3000 BC, some close relatives of the carrot are still grown for their leaves and seeds, for example, parsley, cilantro/coriander, fennel, dill and cumin. Three different types of carrots are depicted, and the states of them that the root can be cooked. The plant appears to have been introduced into Spain by the Moors in the 8th century, in the 10th century, in worldwide locations like West Asia, India and Europe, the roots were purple. The modern carrot originated in Afghanistan at about this time, the Jewish scholar Simeon Seth describes both red and yellow carrots in the 11th century. The 12th-century Arab-Andalusian agriculturist, Ibn al-Awwam, also mentions roots of these colours, cultivated carrots appeared in China in the 14th century, and in Japan in the 18th century. Orange-coloured carrots appeared in the Netherlands in the 17th century, which has been related to the fact that the Dutch flag at the time, the Princes Flag, included orange. These, the carrots, were intended by the English antiquary John Aubrey when he noted in his memoranda
Carrot
–
Carrot
Carrot
–
Seedlings shortly after germination
Carrot
–
Daucus carota umbel (inflorescence). Individual flowers are borne on undivided pedicels originating from a common node.
Carrot
–
Top view of Daucus carota inflorescence, showing umbellets
17.
Parsnip
–
The parsnip is a root vegetable closely related to the carrot and parsley. It is a plant usually grown as an annual. Its long, tuberous root has cream-colored skin and flesh, and left in the ground to mature, in its first growing season, the plant has a rosette of pinnate, mid-green leaves. If unharvested, it produces its flowering stem, topped by an umbel of yellow flowers. By this time, the stem is woody and the tuber is inedible, the seeds are pale brown, flat, and winged. The parsnip is native to Eurasia and it has been used as a vegetable since antiquity and was cultivated by the Romans, although some confusion exists in the literature of the time between parsnips and carrots. It was used as a sweetener before the arrival in Europe of cane sugar and it was introduced into the United States in the 19th century. The parsnip is usually cooked, but can also be eaten raw and it is high in vitamins and minerals, especially potassium. It also contains antioxidants and both soluble and insoluble dietary fiber and it can be cultivated in deep, stone-free soils. It is attacked by the fly and other insect pests, viruses. Handling the stems and foliage can cause a skin if the skin is exposed to sunlight after handling. The parsnip is a plant with a rosette of roughly hairy leaves that has a pungent odor when crushed. Parsnips are grown for their fleshy, edible, cream-colored taproots, the roots are generally smooth, although lateral roots sometimes form. Most are cylindrical, but some cultivars have a bulbous shape. The plants apical meristem produces a rosette of leaves, each with several pairs of leaflets with toothed margins. The lower leaves have stems, the upper ones are stemless. The leaves are once- or twice-pinnate with broad, ovate, sometimes lobed leaflets with toothed margins, the petioles are grooved and have sheathed bases. The floral stem develops in the year and can grow to more than 150 cm tall
Parsnip
–
Parsnip
Parsnip
–
Pastinaca sativa fruits and seeds
Parsnip
–
Illustration from
Johann Georg Sturm 's 1796 Deutschlands Flora in Abbildungen
18.
Senecio jacobaea
–
Senecio jacobaea, is a very common wild flower in the family Asteraceae that is native to northern Eurasia, usually in dry, open places, and has also been widely distributed as a weed elsewhere. In the western United States it is known as tansy ragwort, or tansy. The plant is considered to be biennial but it has the tendency to exhibit perennial properties under certain cultural conditions. The stems are erect, straight, have no or few hairs, the leaves are pinnately lobed and the end lobe is blunt. The many names that include the word stinking arise because of the unpleasant smell of the leaves, the hermaphrodite flower heads are 1. 5–2.5 centimetres diameter, and are borne in dense, flat-topped clusters, the florets are bright yellow. It has a flowering period lasting from June to November. Pollination is by a range of bees, flies and moths. Over a season, one plant may produce 2,000 to 2,500 yellow flowers in 20- to 60-headed, flat-topped corymbs, two subspecies are accepted, Jacobaea vulgaris ssp. vulgaris - the typical plant, with ray florets present. Jacobaea vulgaris ssp. dunensis - the ray florets are missing, Ragwort is abundant in waste land, waysides and grazing pastures. It can be found along road sides, and grows in all cool, Ragwort is native to the Eurasian continent. In Europe it is spread, from Scandinavia to the Mediterranean. In Britain and Ireland it is listed as a weed, in South America it grows in Argentina, in Africa in the north, and on the Asian continent in India and Siberia. It is widespread weed in New Zealand and Australia, in many Australian states ragwort has been declared a noxious weed. This status requires landholders to remove it from their property, by law, the same applies to New Zealand, where farmers sometimes bring in helicopters to spray their farms if the ragwort is too widespread. Ragwort is a plant for the larvae of Cochylis atricapitana, Phycitodes maritima. Ragwort is best known as the food of caterpillars of the cinnabar moth Tyria jacobaeae and they absorb alkaloids from the plant and become distasteful to predators, a fact advertised by the black and yellow warning colours. The red and black, day-flying adult moth is also distasteful to potential predators. The moth is used as a control for ragwort in countries in which it has introduced and become a problem, like New Zealand
Senecio jacobaea
–
Jacobaea vulgaris
Senecio jacobaea
–
Flowering plant with Cinnabar moth caterpillars
Senecio jacobaea
–
Drone fly on ragwort
Senecio jacobaea
19.
Potato
–
The potato is a starchy, tuberous crop from the perennial nightshade Solanum tuberosum. The word potato may refer either to the plant itself or to the edible tuber, in the Andes, where the species is indigenous, there are some other closely related cultivated potato species. Potatoes were introduced to Europe in the half of the 16th century by the Spanish. It is the worlds fourth-largest food crop, following maize, wheat, the green leaves and green skins of tubers exposed to the light are toxic. Wild potato species can be throughout the Americas from the United States to southern Chile. Following centuries of breeding, there are now over a thousand different types of potatoes. However, the importance of the potato is variable and changing rapidly. As of 2007 China led the world in production, and nearly a third of the worlds potatoes were harvested in China. The English word potato comes from Spanish patata, the Spanish Royal Academy says the Spanish word is a compound of the Taíno batata and the Quechua papa. The 16th-century English herbalist John Gerard used the terms bastard potatoes and Virginia potatoes for this species, potatoes are occasionally referred to as Irish potatoes or white potatoes in the United States, to distinguish them from sweet potatoes. The name spud for a small potato comes from the digging of soil prior to the planting of potatoes, the word spud traces back to the 16th century. It subsequently transferred over to a variety of digging tools, around 1845, the name transferred to the tuber itself. It was Mario Peis 1949 The Story of Language that can be blamed for the false origin. Pei writes, the potato, for its part, was in disrepute some centuries ago, some Englishmen who did not fancy potatoes formed a Society for the Prevention of Unwholesome Diet. The initials of the words in this title gave rise to spud. Like most other pre-20th century acronymic origins, this is false, Potato plants are herbaceous perennials that grow about 60 cm high, depending on variety, with the leaves dying back after flowering, fruiting and tuber formation. They bear white, pink, red, blue, or purple flowers with yellow stamens, in general, the tubers of varieties with white flowers have white skins, while those of varieties with colored flowers tend to have pinkish skins. Potatoes are mostly cross-pollinated by insects such as bumblebees, which carry pollen from other potato plants, tubers form in response to decreasing day length, although this tendency has been minimized in commercial varieties
Potato
–
Potato
Potato
–
Flowers of a potato plant
Potato
–
Russet potatoes
Potato
–
Potato plants
20.
Peony
–
The peony or paeony is a flowering plant in the genus Paeonia, the only genus in the family Paeoniaceae. They are native to Asia, Europe and Western North America, scientists differ on the number of species that can be distinguished ranging from 25 to 40, although the current consensus is 33 known species. The relationships between the species need to be further clarified, most are herbaceous perennial plants 0. 25–1 metre tall, but some are woody shrubs 0. 25–3.5 metres tall. They have compound, deeply lobed leaves and large, often fragrant flowers, in ranging from purple red to white or yellow, in late spring. Peonies are among the most popular plants in temperate regions. Herbaceous peonies are also sold as cut flower on a scale, although generally only available in late spring. All Paeoniaceae are deciduous perennial herbs or shrubs, with thick roots and thin roots for gathering water. Some species are caespitose, because the crown produces adventitous buds and they have rather large compound leaves without glands and stipules, and with anomocytic stomata. In the woody species the new growth emerges from scaly buds on the previous flush or from the crown of the rootstock, the large bisexual flowers are mostly single at the end of the stem. In P. emodi, P. lactiflora, P. veitchii and many of the cultivars these contributed to, Flowers close at night or when the sky is overcast. Each flower is subtended by a number of bracts, that may form a sort of involucre, has 3-7 tough free sepals and mostly 5-8 and these categories however are intergrading, making it difficult to assign some of them, and the number of these parts may vary. Within the circle of stamens is a more or less prominent, lobed disc, within the disk is a varying number of separate carpels, which have a very short style and a decurrent stigma. Each of these develops into a dry fruit, which open with a lengthwise suture, the annual growth is predetermined, if the growing tip of a shoot is removed, no new buds will develop that season. Paeoniaceae are dependent on C3 carbon fixation and they contain ellagic acid, myricetin, ethereal oils and flavones, as well as crystals of calcium oxalate. The wax tubules that are formed primarily consist of palmitone, the basic chromosome number is five. About half of the species of the section Paeonia however is tetraploid, both allotetraploids and autotetraploids are known, and some diploid species are also of hybrid origin. The family name Paeoniaceae was first used by Friedrich K. L, rudolphi in 1830, following a suggestion by Friedrich Gottlieb Bartling that same year. The family had given other names a few years earlier
Peony
–
Peony
Peony
–
Peony close-up
Peony
–
A cultivated hybrid peony
Peony
–
Paeonia caucasica
21.
Hosta
–
Hosta is a genus of plants commonly known as hostas, plantain lilies and occasionally by the Japanese name giboshi. Hostas are widely cultivated as shade-tolerant foliage plants, the genus is currently placed in the family Asparagaceae, subfamily Agavoideae, and is native to northeast Asia. Like many lilioid monocots, the genus was classified in the Liliaceae. The genus was named by Austrian botanist Leopold Trattinnick in 1812, Hostas are herbaceous perennial plants, growing from rhizomes or stolons, with broad lanceolate or ovate leaves varying widely in size by species from 1–18 in long and 0. 75–12 in broad. The smallest varieties are called miniatures, variation among the numerous cultivars is even greater, with clumps ranging from less than four in across and three in high to more than six ft across and four ft high. Leaf color in wild species is green, although some species are known for a glaucous waxy leaf coating that gives a blue appearance to the leaf. Some species have a white coating covering the underside of the leaves. Natural mutations of native species are known with yellow-green colored leaves or with leaf variegation, variegated plants very often give rise to sports that are the result of the reshuffling of cell layers during bud formation, producing foliage with mixed pigment sections. In seedlings variegation is generally derived by chloroplast transfer and is not a genetically inheritable trait. The flowers are produced on erect scapes, generally taller than the leaf mound, the individual flowers are usually pendulous,0. 75–2 in long, with six petals, white, lavender, or violet in color and usually scentless. The only strongly fragrant species is Hosta plantaginea, which has flowers up to four in long, it is also unusual in that the flowers open in the evening. This species blooms in summer and is sometimes known as August Lily. Taxonomists differ on the number of Hosta species, there may be as many as 45, accordingly, the list of species given here may be taken loosely. The genus may be divided into three subgenera. Interspecific hybridization occurs since all the species have the same chromosome number, many cultivated hostas formerly described as species have been reduced to cultivars, these often have their names conserved, and retain Latin names which resemble species names. Accepted species as of October 2014 Hostas are widely cultivated, being useful in the garden as shade-tolerant plants whose striking foliage provides a focal point. Though Hosta plantaginea originates in China, most of the species provide the modern plants were introduced from Japan to Europe by Philipp Franz von Siebold in the mid-19th century. Newer species have been discovered on the Korean peninsula as well, cultivars with golden- or white-variegated leaves are especially prized
Hosta
–
Hosta
Hosta
22.
Mentha
–
Mentha is a genus of plants in the family Lamiaceae. It is estimated that 13 to 18 species exist, and the distinction between species is still unclear. Hybridization between some of the species occur naturally, many other hybrids, as well as numerous cultivars, are known. The genus has a distribution across Europe, Africa, Asia, Australia. Mints are aromatic, almost exclusively perennial, rarely annual herbs and they have wide-spreading underground and overground stolons and erect, square, branched stems. The leaves are arranged in pairs, from oblong to lanceolate, often downy. Leaf colors range from green and gray-green to purple, blue. The flowers are white to purple and produced in whorls called verticillasters. The corolla is two-lipped with four lobes, the upper lobe usually the largest. The fruit is a nutlet, containing one to four seeds, while the species that make up the Mentha genus are widely distributed and can be found in many environments, most grow best in wet environments and moist soils. Mints will grow 10–120 cm tall and can spread over an indeterminate area, due to their tendency to spread unchecked, some mints are considered invasive. The list below all of the taxa recognized as species in recent works on Mentha. No author has recognized all of them, as with all biological classifications of plants, this list can go out of date at a moments notice. Common names are given for species that have them. Synonyms, along with cultivars and varieties, are given in articles on the species, Mentha is a member of the tribe Mentheae in the subfamily Nepetoideae. The tribe contains about 65 genera, and relationships within it remain obscure, authors have disagreed on the circumscription of Mentha. Some authors have excluded M. cervina from the genus, M. cunninghamii has also been excluded by some authors, even in some recent treatments of the genus. In 2004, a phylogenetic study indicated both of these species should be included in Mentha
Mentha
–
Mentha
Mentha
–
The mentha x piperita hybrid, known as "chocolate mint."
Mentha
–
Mentha x gracilis and M. rotundifolia: The steel ring is to control the spread of the plant.
Mentha
–
A jar of mint jelly: Mint jelly is a traditional condiment served with lamb dishes.
23.
Fern
–
A fern is a member of a group of about 10,560 known extant species of vascular plants that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i. e. having certain tissue that conducts water and they have branched stems and leaves like other vascular plants. These are megaphylls, which are more complex than the simple microphylls of clubmosses, most ferns are Leptosporangiate ferns, sometimes denominated the true ferns, they produce what are called fiddleheads that uncoil and expand into fronds. Ferns as defined herein are the ferns sensu lato, being all of the Monilophytes, the Pteridophytes traditionally denominate all seedless vascular plants, of which the Monilophytes predominate, although some recent authors have used it to refer strictly to the Monilophytes alone. The fern Osmunda claytoniana is a paramount example of evolutionary stasis, paleontological evidence indicates it has remained unchanged, even at the level of fossilized nuclei and chromosomes, for at least 180 million years. Ferns are not of major importance, but some are gathered for food or medicine, grown for food, medicine, or as ornamentals. They have been the subject of research for their ability to remove some pollutants from the atmosphere. Some fern species are significant weeds and they also play certain roles in mythology and art. Ferns are vascular plants differing from lycophytes by having true leaves and they differ from seed plants in their mode of reproduction—lacking flowers and seeds. Like all land plants, they have a life cycle referred to as alternation of generations, characterized by alternating diploid sporophytic, the diploid sporophyte has 2n paired chromosomes, where n varies from species to species. The haploid gametophyte has n unpaired chromosomes, i. e. half the number of the sporophyte, the gametophyte of ferns is a free-living organism, whereas the gametophyte of the gymnosperms and angiosperms is dependent on the sporophyte. The life cycle of a typical fern proceeds as follows, A diploid sporophyte produces haploid spores by meiosis. A spore grows into a haploid gametophyte by mitosis, the gametophyte typically consists of a photosynthetic prothallus. The gametophyte produces gametes by mitosis, a mobile, flagellate sperm fertilizes an egg that remains attached to the prothallus. The fertilized egg is now a diploid zygote and grows by mitosis into a diploid sporophyte, like the sporophytes of seed plants, those of ferns consist of stems, leaves and roots. Stems, Fern stems are often referred to as rhizomes, even though they grow underground only in some of the species, epiphytic species and many of the terrestrial ones have above-ground creeping stolons, and many groups have above-ground erect semi-woody trunks. These can reach up to 20 metres tall in a few species, leaf, The green, photosynthetic part of the plant is technically a megaphyll and in ferns, it is often referred to as a frond. New leaves typically expand by the unrolling of a tight spiral called a crozier or fiddlehead fern and this uncurling of the leaf is termed circinate vernation
Fern
Fern
–
Gametophyte (
thalloid green mass) and sporophyte (ascendent frond) of
Onoclea sensibilis
Fern
–
Ferns at the Royal Melbourne Botanical Gardens
Fern
–
Tree ferns, probably
Dicksonia antarctica, growing in Nunniong, Australia
24.
Poaceae
–
Poaceae or Gramineae is a large and nearly ubiquitous family of monocotyledonous flowering plants known as grasses. Poaceae includes the cereal grasses, bamboos and the grasses of natural grassland and cultivated lawns, Grasses have stems that are hollow except at the nodes and narrow alternate leaves borne in two ranks. The lower part of each leaf encloses the stem, forming a leaf-sheath, with ca 780 genera and around 12,000 species, Poaceae are the fifth-largest plant family, following the Asteraceae, Orchidaceae, Fabaceae and Rubiaceae. Grasslands such as savannah and prairie grasses are dominant are estimated to constitute 40. 5% of the land area of the Earth, excluding Greenland. Grasses are also an important part of the vegetation in many habitats, including wetlands, forests. Though commonly called grasses, seagrasses, rushes, and sedges fall outside this family, the rushes and sedges are related to the Poaceae, being members of the order Poales, but the seagrasses are members of order Alismatales. The name Poaceae was given by John Hendley Barnhart in 1895, based on the tribe Poeae described in 1814 by Robert Brown, the term is derived from the Ancient Greek πόα. Grasses include some of the most versatile plant life-forms, a cladogram shows subfamilies and approximate species numbers in brackets, Before 2005, fossil findings indicated that grasses evolved around 55 million years ago. Recent findings of grass-like phytoliths in Cretaceous dinosaur coprolites have pushed this back to 66 million years ago. In 2011, revised dating of the origins of the rice tribe Oryzeae suggested a date as early as 107 to 129 Mya, a multituberculate mammal with grass-eating adaptations seems to suggest that grasses were already around at 120 mya. This separation occurred within the short time span of about 4 million years. Grass leaves are always alternate and distichous, and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem, the leaf blades of many grasses are hardened with silica phytoliths, which discourage grazing animals, some, such as sword grass, are sharp enough to cut human skin. A membranous appendage or fringe of hairs called the ligule lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath, flowers of Poaceae are characteristically arranged in spikelets, each having one or more florets. The spikelets are further grouped into panicles or spikes, the part of the spikelet that bears the florets is called the rachilla. A spikelet consists of two bracts at the base, called glumes, followed by one or more florets, a floret consists of the flower surrounded by two bracts, one external—the lemma—and one internal—the palea. The flowers are usually hermaphroditic—maize being an important exception—and anemophilous or wind-pollinated, the perianth is reduced to two scales, called lodicules, that expand and contract to spread the lemma and palea, these are generally interpreted to be modified sepals. This complex structure can be seen in the image on the right, the fruit of grasses is a caryopsis, in which the seed coat is fused to the fruit wall
Poaceae
Poaceae
–
Grass flowers
Poaceae
–
Setaria verticillata from
Panicoideae
Poaceae
–
Tragus roxburghii from
Chloridoideae
25.
Woody plant
–
A woody plant is a plant that produces wood as its structural tissue. Woody plants are usually either trees, shrubs, or lianas and these are usually perennial plants whose stems and larger roots are reinforced with wood produced from secondary xylem. The main stem, larger branches, and roots of plants are usually covered by a layer of bark. Wood is a structural cellular adaptation that allows plants to grow from above ground stems year after year. Wood is primarily composed of cells with cell walls made of cellulose. Xylem is a vascular tissue which moves water and nutrients from the roots to the leaves, however, in some monocotyledons such as palms and dracaenas, the wood is formed in bundles scattered through the interior of the trunk. Woody herbs are herbaceous plants that develop hard woody stems and they include such plants as Uraria picta and certain species in family Polygonaceae. These herbs are not truly woody but have densely packed stem tissue. Other herbaceous plants have woody stems called a caudex, which is a stem base often found in plants that grow in alpine or dry environments. Under specific conditions, woody plants may decay or may in time become petrified wood, the symbol for a woody plant, based on Species Plantarum by Linnaeus is, which is also the astronomical symbol for the planet Saturn
Woody plant
–
A section of
rosemary stem, an example of a woody plant, showing a typical wood structure.
26.
Tree
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In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a group but include a variety of plant species that have independently evolved a woody trunk. In looser senses, the palms, the tree ferns, bananas. Trees tend to be long-lived, some reaching several thousand years old, the tallest known tree, a coast redwood named Hyperion, stands 115.6 m high. Trees have been in existence for 370 million years and it is estimated that there are just over 3 trillion mature trees in the world. A tree typically has many secondary branches supported clear of the ground by the trunk and this trunk typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier, below the ground, the roots branch and spread out widely, they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, the divide into smaller branches and shoots. The shoots typically bear leaves, which light energy and convert it into sugars by photosynthesis, providing the food for the trees growth. Flowers and fruit may also be present, but some trees, such as conifers, instead have pollen cones and seed cones, others, such as tree ferns, trees play a significant role in reducing erosion and moderating the climate. They remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues, trees and forests provide a habitat for many species of animals and plants. Tropical rainforests are one of the most biodiverse habitats in the world, trees provide shade and shelter, timber for construction, fuel for cooking and heating, and fruit for food as well as having many other uses. In parts of the world, forests are shrinking as trees are cleared to increase the amount of available for agriculture. Because of their longevity and usefulness, trees have always revered, with sacred groves in various cultures. Although tree is a term of common parlance, there is no universally recognised precise definition of what a tree is, either botanically or in common language. In its broadest sense, a tree is any plant with the form of an elongated stem, or trunk. Trees are also defined by height, with smaller plants from 0.5 to 10 m being called shrubs
Tree
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Common ash (
Fraxinus excelsior), a
deciduous broad-leaved (
angiosperm) tree
Tree
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European larch (
Larix decidua), a
coniferous tree which is also
deciduous
Tree
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Lepidodendron, an extinct
lycophyte tree
Tree
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Diagram of
secondary growth in a
eudicot or
coniferous tree showing idealised vertical and horizontal sections. A new layer of
wood is added in each growing season, thickening the stem, existing branches and roots.
27.
Shrub
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A shrub or bush is a small to medium-sized woody plant. It is distinguished from a tree by its multiple stems and shorter height, plants of many species may grow either into shrubs or trees, depending on their growing conditions. Small, low shrubs, generally less than 2 m tall, such as lavender, periwinkle, an area of cultivated shrubs in a park or a garden is known as a shrubbery. When clipped as topiary, suitable species or varieties of shrubs develop dense foliage, many shrubs respond well to renewal pruning, in which hard cutting back to a stool results in long new stems known as canes. Other shrubs respond better to selective pruning to reveal their structure, shrubs in common garden practice are generally considered broad-leaved plants, though some smaller conifers such as mountain pine and common juniper are also shrubby in structure. Species that grow into a shrubby habit may be deciduous or evergreen
Shrub
–
A
broom shrub in flower
Shrub
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A
rhododendron shrubbery in
Sheringham Park
28.
Vine
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A vine in the narrowest sense is the grapevine, but more generally it can refer to any plant with a growth habit of trailing or scandent stems, lianas or runners. The word also can refer to such stems or runners themselves, in the United Kingdom, the term vine applies almost exclusively to the grapevine. The term climber is used for all climbing plants, certain plants always grow as vines, while a few grow as vines only part of the time. For instance, poison ivy and bittersweet can grow as low shrubs when support is not available, a vine displays a growth form based on long stems. This has been a successful growth form for plants such as kudzu and Japanese honeysuckle. There are some tropical vines that develop skototropism, and grow away from the light, growth away from light allows the vine to reach a tree trunk, which it can then climb to brighter regions. The vine growth form may also enable plants to large areas quickly. This is the case with periwinkle and ground ivy and it is also an adaptation to life in areas where small patches of fertile soil are adjacent to exposed areas with more sunlight but little or no soil. A vine can root in the soil but have most of its leaves in the brighter, exposed area, the evolution of a climbing habit has been implicated as a key innovation associated with the evolutionary success and diversification of a number of taxonomic groups of plants. It has evolved independently in several plant families, using many different climbing methods such as and it directs its stem into a crevice in the bark of fibrous barked trees where the stem adopts a flattened profile and grows up the tree underneath the host trees outer bark. The fetterbush then sends out branches that emerge near the top of the tree and these may be divided into woody vines or lianas, such as wisteria, kiwifruit, and common ivy, and herbaceous vines, such as morning glory. One odd group of vining plants is the fern genus Lygodium, the stem does not climb, but rather the fronds do. The fronds unroll from the tip, and theoretically never stop growing, they can form thickets as they unroll over other plants, rockfaces, gardeners can use the tendency of climbing plants to grow quickly. If a plant display is wanted quickly, a climber can achieve this, climbers can be trained over walls, pergolas, fences, etc. Climbers can be grown over other plants to provide additional attraction, artificial support can also be provided. Some climbers climb by themselves, others need work, such as tying them in, vines widely differ in size, form and evolutionary origin. Darwin classified climbing groups based on their climbing method and he classified five classes of vines including twining plants, leaf climbers, tendril bearers, root climbers and hook climbers. Vines are unique in that they have multiple origins and a wide range of phenotypic plasticity
Vine
–
A
tendril
Vine
–
Climbing plant covering a chimney
Vine
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Retaining wall covered by vines
Vine
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A large vine on the street in
Sochi, Russia
29.
Pioneer species
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Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rock into soil for other plants. Clear water - algae, mosses, freshwater eel grass, soil fauna, ranging from microscopic protists to larger invertebrates, have a role in soil formation and nutrient cycling. Bacteria and fungi are the most important groups in the breakdown of organic detritus left by primary producing plants such as soil, moss. Soil invertebrates enhance fungal activity by breaking down detritus, as soil develops, earthworms and ants alter soil characteristics. Worm burrows aerate soil and ant hills alter sediment particle size dispersal, though vertebrates in general would not be considered pioneer species, there are exceptions. Natterjack toads are specialists in open, sparsely vegetated habitats which may be at an early seral stage, wide-ranging generalists visit early succession stage habitats, but are not obligate species of those habitats because they use a mosaic of different habitats. Vertebrates can effect early seral stages, fossorial mammals could alter soil and plant community development. In a profound example, a seabird colony transfers considerable nitrogen into infertile soils, a keystone species may facilitate the introduction of pioneer species by creating new niches. For example, beavers may flood an area, allowing new species to immigrate, common examples of the plants in such areas include, Birch - Betula spp. Graminoids, forbs, and wildflowers - native, introduced, and invasive species, such as fire dependent seed, cone, and resprouter chaparral genera
Pioneer species
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Centaurea maculosa, an example of pioneer species
Pioneer species
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Pioneer species of plant growing on a recently erupted lava flow in
Hawaii
