Polygala serpyllifolia, the heath milkwort, is a native perennial of heaths and grassy places. Height to 25 cm; the lower leaves are in opposite pairs. Flowers May to August. Wild Flowers of Britain by Roger Phillips
Glossary of botanical terms
This glossary of botanical terms is a list of terms relevant to botany and plants in general. Terms of plant morphology are included here as well as at the related Glossary of plant morphology and Glossary of leaf morphology. See List of Latin and Greek words used in systematic names. You can help by adding illustrations. Ab- A prefix meaning "from, away from, or outside". Abaxial The surface of an organ facing away from the organ's axis, e.g. the lower surface of a lateral organ such as a leaf or petal. Abort To abandon development of a structure or organ. Abscission The shedding of an organ, mature or aged, e.g. a ripe fruit or an old leaf. Abscission zone A specialised layer of tissue that allows an organ to be shed by abscission when it is ripe or senescent. Formed, for example, at the base of a petiole or pedicel. Acaulescent Having no apparent stem, or at least none visible above the ground surface. Examples include some species of Agave and Attalea. Accrescent Increasing in size with age, such as a calyx that continues to grow after the corolla has fallen, for example in Physalis peruviana.
-aceae A suffix added to the stem of a generic name to form the name of a taxonomic family. Achene A dry, 1-seeded indehiscent fruit, e.g. in the genus Ranunculus. Acicular Slender or needle-shaped. Acropetal Moving from roots to leaves, e.g. of molecular signals in plants. Acrophyll The regular leaves of a mature plant, produced above the base. Acrostichoid Covering the entire abaxial surface of a frond densely so, as in Elaphoglossum and Acrostichum. Actino- A prefix that indicates a radial pattern, form, or morphology. Actinodromous Palmate or radially arranged venation with three or more primary veins arising at or near the base of the leaf and either reaching the margin or not. Actinomorphic Regular. Applies e.g. to steles and flowers in which the perianth segments within each whorl are alike in size and shape. Compare regular. Aculeate Armed with prickles, e.g. the stem of a rose. Acuminate Tapering to a point. Acute Sharply pointed. Compare obtuse. Ad- A prefix meaning "near or towards". Adaxial The surface of an organ facing towards the organ's axis, e.g. the upper surface of a lateral organ such as a leaf or petal.
Adnate Grown or fused to an organ of a different kind along a margin, e.g. a stamen fused to a petal. Compare connate. Adventitious A structure produced in an abnormal position, e.g. an adventitious bud produced from a stem rather than from the axil of a leaf. Adventive Introduced accidentally. Aerial Of the air. Aestivation The arrangement of sepals and petals or their lobes in an unexpanded flower bud. Compare vernation, the arrangement of leaves in a bud. aff. With affinity to others, akin to. Aggregate fruit A cluster of fruits formed from the free carpels of one flower, e.g. a blackberry. Compare multiple fruit. Agricultural weed See weed. alate Having a wing or wings. Albumen An older name for the endosperm of flowering plants. Except for being a storage tissue for nutrients, it is not at all like the albumen of animal embryos. Albuminous Containing endosperm. -ales A suffix added to the stem of a generic name or descriptive name to form the name of a taxonomic order. Alien A plant introduced to an area outside its natural range.
Synonymous to or used in combination with foreign, non-native, non-indigenous. Alkaloid A molecule with a nitrogenous base used as a drug, e.g. morphine and strychnine, each of which occurs in certain plants. Alternate 1. Leaves or flowers borne singly including spiralled parts. 2. When something occurs between something else, e.g. stamens alternating with petals. Compare opposite. Ament A synonym of catkin. Amphitropous When the ovule is bent so that both ends are near each other. Compare anatropous and orthotropous. Amplexicaul With the base dilated and clasping the stem of leaves. Anastomose Branching and rejoining, as with leaf venation. Anastomosis A connection or fusion of two or more veins that are diverging or branching, thereby forming a network. Anatropous When an ovule is inverted so that the micropyle faces the placenta. Compare amphitropous, orthotropous. Androdioecious Of plants, having male flowers on separate individuals. Compare andromonoecious, polygamodioecious, polygamomonoecious, polygamous.
Androecium Male parts of flower. Compare gynoecium. Abbreviation: A. For instance A 3+3 indicates 6 stamens in two whorls. Androgynophore A stalk bearing both the androecium and gynoecium of a flower above the level of insertion of the perianth. Androgynous With male and female flowers in the same inflorescence. Androphore The stalk or column supporting the stamens in certain flowers. Andromonoecious Having bisexual flowers and male flowers on the same individual plant. Compare gynomonoecious, polygamodioecious, polygamomonoecious, polygamous. Anemophily Pollination by wind. Angiosperm A flowering plant. Anisomery The condition of hav
Binomial nomenclature called binominal nomenclature or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages. Such a name is called a binomen, binominal name or a scientific name; the first part of the name – the generic name – identifies the genus to which the species belongs, while the second part – the specific name or specific epithet – identifies the species within the genus. For example, humans belong within this genus to the species Homo sapiens. Tyrannosaurus rex is the most known binomial; the formal introduction of this system of naming species is credited to Carl Linnaeus beginning with his work Species Plantarum in 1753. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus; the application of binomial nomenclature is now governed by various internationally agreed codes of rules, of which the two most important are the International Code of Zoological Nomenclature for animals and the International Code of Nomenclature for algae and plants.
Although the general principles underlying binomial nomenclature are common to these two codes, there are some differences, both in the terminology they use and in their precise rules. In modern usage, the first letter of the first part of the name, the genus, is always capitalized in writing, while that of the second part is not when derived from a proper noun such as the name of a person or place. Both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a binomial name is given, at least when it is first mentioned, the date of publication may be specified. In zoology "Patella vulgata Linnaeus, 1758"; the name "Linnaeus" tells the reader who it was that first published a description and name for this species of limpet. "Passer domesticus". The original name given by Linnaeus was Fringilla domestica; the ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, although nomenclatorial catalogs include such information.
In botany "Amaranthus retroflexus L." – "L." is the standard abbreviation used in botany for "Linnaeus". "Hyacinthoides italica Rothm. – Linnaeus first named this bluebell species Scilla italica. The name is composed of two word-forming elements: "bi", a Latin prefix for two, "-nomial", relating to a term or terms; the word "binomium" was used in Medieval Latin to mean a two-term expression in mathematics. Prior to the adoption of the modern binomial system of naming species, a scientific name consisted of a generic name combined with a specific name, from one to several words long. Together they formed a system of polynomial nomenclature; these names had two separate functions. First, to designate or label the species, second, to be a diagnosis or description. In a simple genus, containing only two species, it was easy to tell them apart with a one-word genus and a one-word specific name; such "polynomial names" may sometimes look like binomials, but are different. For example, Gerard's herbal describes various kinds of spiderwort: "The first is called Phalangium ramosum, Branched Spiderwort.
The other... is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia". The Latin phrases are short descriptions, rather than identifying labels; the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words. The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné, more known by his Latinized name Carl Linnaeus, it was in his 1753 Species Plantarum that he first began using a one-word "trivial name" together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as specific name; the Bauhins' genus names were retained in many of these, but the descriptive part was reduced to a single word. Linnaeus's trivial names introduced an important new idea, namely that the function of a name could be to give a species a unique label; this meant. Thus Gerard's Phalangium ephemerum virginianum became Tradescantia virgi
Plants are multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. Plants were treated as one of two kingdoms including all living things that were not animals, all algae and fungi were treated as plants. However, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes. By one definition, plants form the clade Viridiplantae, a group that includes the flowering plants and other gymnosperms and their allies, liverworts and the green algae, but excludes the red and brown algae. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria, their chloroplasts contain b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ability to produce normal amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although asexual reproduction is common.
There are about 320 thousand species of plants, of which the great majority, some 260–290 thousand, are seed plants. Green plants provide a substantial proportion of the world's molecular oxygen and are the basis of most of Earth's ecosystems on land. Plants that produce grain and vegetables form humankind's basic foods, have been domesticated for millennia. Plants have many cultural and other uses, as ornaments, building materials, writing material and, in great variety, they have been the source of medicines and psychoactive drugs; the scientific study of plants is known as a branch of biology. All living things were traditionally placed into one of two groups and animals; this classification may date from Aristotle, who made the distincton between plants, which do not move, animals, which are mobile to catch their food. Much when Linnaeus created the basis of the modern system of scientific classification, these two groups became the kingdoms Vegetabilia and Animalia. Since it has become clear that the plant kingdom as defined included several unrelated groups, the fungi and several groups of algae were removed to new kingdoms.
However, these organisms are still considered plants in popular contexts. The term "plant" implies the possession of the following traits multicellularity, possession of cell walls containing cellulose and the ability to carry out photosynthesis with primary chloroplasts; when the name Plantae or plant is applied to a specific group of organisms or taxon, it refers to one of four concepts. From least to most inclusive, these four groupings are: Another way of looking at the relationships between the different groups that have been called "plants" is through a cladogram, which shows their evolutionary relationships; these are not yet settled, but one accepted relationship between the three groups described above is shown below. Those which have been called "plants" are in bold; the way in which the groups of green algae are combined and named varies between authors. Algae comprise several different groups of organisms which produce food by photosynthesis and thus have traditionally been included in the plant kingdom.
The seaweeds range from large multicellular algae to single-celled organisms and are classified into three groups, the green algae, red algae and brown algae. There is good evidence that the brown algae evolved independently from the others, from non-photosynthetic ancestors that formed endosymbiotic relationships with red algae rather than from cyanobacteria, they are no longer classified as plants as defined here; the Viridiplantae, the green plants – green algae and land plants – form a clade, a group consisting of all the descendants of a common ancestor. With a few exceptions, the green plants have the following features in common, they undergo closed mitosis without centrioles, have mitochondria with flat cristae. The chloroplasts of green plants are surrounded by two membranes, suggesting they originated directly from endosymbiotic cyanobacteria. Two additional groups, the Rhodophyta and Glaucophyta have primary chloroplasts that appear to be derived directly from endosymbiotic cyanobacteria, although they differ from Viridiplantae in the pigments which are used in photosynthesis and so are different in colour.
These groups differ from green plants in that the storage polysaccharide is floridean starch and is stored in the cytoplasm rather than in the plastids. They appear to have had a common origin with Viridiplantae and the three groups form the clade Archaeplastida, whose name implies that their chloroplasts were derived from a single ancient endosymbiotic event; this is the broadest modern definition of the term'plant'. In contrast, most other algae not only have different pigments but have chloroplasts with three or four surrounding membranes, they are not close relatives of the Archaeplastida having acquired chloroplasts separately from ingested or symbiotic green and red algae. They are thus not included in the broadest modern definition of the plant kingdom, although they were in the past; the green plants or Viridiplantae were traditionally divided into the green algae (including
The flowering plants known as angiosperms, Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 64 orders, 416 families 13,164 known genera and c. 369,000 known species. Like gymnosperms, angiosperms are seed-producing plants. However, they are distinguished from gymnosperms by characteristics including flowers, endosperm within the seeds, the production of fruits that contain the seeds. Etymologically, angiosperm means a plant; the term comes from the Greek words sperma. The ancestors of flowering plants diverged from gymnosperms in the Triassic Period, 245 to 202 million years ago, the first flowering plants are known from 160 mya, they diversified extensively during the Early Cretaceous, became widespread by 120 mya, replaced conifers as the dominant trees from 100 to 60 mya. Angiosperms differ from other seed plants in several ways, described in the table below; these distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants and the most commercially important group to humans.
Angiosperm stems are made up of seven layers. The amount and complexity of tissue-formation in flowering plants exceeds that of gymnosperms; the vascular bundles of the stem are arranged such that the phloem form concentric rings. In the dicotyledons, the bundles in the young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium. By the formation of a layer of cambium between the bundles, a complete ring is formed, a regular periodical increase in thickness results from the development of xylem on the inside and phloem on the outside; the soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Owing to differences in the character of the elements produced at the beginning and end of the season, the wood is marked out in transverse section into concentric rings, one for each season of growth, called annual rings.
Among the monocotyledons, the bundles are more numerous in the young stem and are scattered through the ground tissue. They once formed the stem increases in diameter only in exceptional cases; the characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, provide the most trustworthy external characteristics for establishing relationships among angiosperm species; the function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The floral apparatus may arise terminally from the axil of a leaf; as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. More the flower-bearing portion of the plant is distinguished from the foliage-bearing or vegetative portion, forms a more or less elaborate branch-system called an inflorescence. There are two kinds of reproductive cells produced by flowers. Microspores, which will divide to become pollen grains, are the "male" cells and are borne in the stamens.
The "female" cells called megaspores, which will divide to become the egg cell, are contained in the ovule and enclosed in the carpel. The flower may consist only of these parts, as in willow, where each flower comprises only a few stamens or two carpels. Other structures are present and serve to protect the sporophylls and to form an envelope attractive to pollinators; the individual members of these surrounding structures are known as petals. The outer series is green and leaf-like, functions to protect the rest of the flower the bud; the inner series is, in general, white or brightly colored, is more delicate in structure. It functions to attract bird pollinators. Attraction is effected by color and nectar, which may be secreted in some part of the flower; the characteristics that attract pollinators account for the popularity of flowers and flowering plants among humans. While the majority of flowers are perfect or hermaphrodite, flowering plants have developed numerous morphological and physiological mechanisms to reduce or prevent self-fertilization.
Heteromorphic flowers have short carpels and long stamens, or vice versa, so animal pollinators cannot transfer pollen to the pistil. Homomorphic flowers may employ a biochemical mechanism called self-incompatibility to discriminate between self and non-self pollen grains. In other species, the male and female parts are morphologically separated, developing on different flowers; the botanical term "Angiosperm", from the Ancient Greek αγγείον, angeíon and σπέρμα, was coined in the form Angiospermae by Paul Hermann in 1690, as the name of one of his primary divisions of the plant kingdom. This included flowering plants possessing seeds enclosed in capsules, distinguished from his Gymnospermae, or flowering plants with achenial or schizo-carpic fruits, the whole fruit or each of its pieces being here regarded as a seed and naked; the term and its antonym were maintained by Carl Linnaeus with the same sense, but with restricted application, in the names of the orders of his class Didynamia. Its use with any
Polygala is a large genus of flowering plants belonging to the family Polygalaceae. They are known as milkworts or snakeroots; the genus is distributed throughout much of the world in temperate zones and the tropics. The genus name Polygala comes from the ancient Greek "much milk", as the plant was thought to increase milk yields in cattle. Polygala includes annual and perennial plants, shrubs and trees; the roots have a scent reminiscent of wintergreen. The leaf blades are undivided and smooth-edged, are alternately arranged in most species; the inflorescence is a spikelike array of several flowers. The flower is bilateral in shape, with two large petal-like sepals on the sides called the "wings", three smaller sepals behind. There are three petals in shades of reddish purple, which are joined at the bases; the lower of the three is the keel petal, "boat-shaped, cucullate, or helmet-shaped". The keel petal may have a fringe on the tip. Stamens and style are within the curve of the keel petal; the fruit is a capsule, sometimes winged.
It contains two seeds, which are black and tipped with a large white aril. One polygala is the Fringed Polygala, found in coniferous forests. Polygala species are used as food plants by the larvae of some Lepidoptera species including large grizzled skipper; some species are valued in cultivation. The hybrid evergreen shrub P. × dalmaisiana has gained the Royal Horticultural Society's Award of Garden Merit. The reported number of valid species in the genus varies from about 350 to 500 to 725 or 730; the Americas have the most species South America, with Africa second in diversity and Asia third. Species include: Polygala acanthoclada – desert polygala Polygala africana Polygala alba – white milkwort Polygala alpestris – alpine milkwort Polygala amara – bitter milkwort Polygala amarella – dwarf milkwort Polygala ambigua – whorled milkwort Polygala apopetala Polygala arillata Polygala arvensis – Australian milkwort Polygala asbestina Polygala balduinii – Baldwin's milkwort Polygala barbeyana – blue milkwort Polygala bifoliata Polygala boykinii – Boykin's milkwort Polygala brevifolia – littleleaf milkwort Polygala butyracea – black beniseed Polygala calcarea – chalk milkwort Polygala californica – California milkwort Polygala canaliculata Polygala chamaebuxus – shrubby milkwort Polygala chapmanii – Chapman's milkwort Polygala chinensis Polygala comosa – tufted milkwort Polygala cornuta – Sierra milkwort Polygala cowellii – tortuguero, violet tree Polygala crassitesta Polygala crenata – scalloped milkwort Polygala crotalarioides Polygala crucianelloides – Caribbean milkwort Polygala cruciata – drumheads Polygala curtissii – Curtiss' milkwort Polygala cymosa – tall pinebarren milkwort Polygala × dalmaisiana Polygala dasyphylla Polygala eriocephala Polygala erubescens Polygala exsquarrosa Polygala floribunda Polygala fruticosa – featherdusters, heart-leaved polygala, ithethe Polygala gerrardii Polygala glandulosa – glandular milkwort Polygala glochidiata – tropical milkwort Polygala grandiflora – showy milkwort Polygala hecatantha – West Indian milkwort Polygala helenae Polygala hemipterocarpa – winged milkwort Polygala heterorhyncha – beaked spiny polygala Polygala hookeri – Hooker's milkwort Polygala hottentotta – small purple broom Polygala incarnata – procession flower Polygala intermontana – Intermountain milkwort Polygala japonica Polygala karensium Polygala klotzschii Polygala kuriensis Polygala langebergensis Polygala lasiosepala Polygala leptocaulis – swamp milkwort Polygala leptostachys – Georgia milkwort Polygala lewtonii – Lewton's polygala Polygala linariifolia – native milkwort Polygala lindheimeri – shrubby milkwort Polygala longicaulis – longstem milkwort Polygala longifolia Polygala lutea – orange milkwort Polygala macowaniana Polygala macradenia – glandleaf milkwort Polygala major Polygala maravillasensis – Maravillas milkwort Polygala mariana – Maryland milkwort Polygala microphylla Polygala monspeliaca – annual milkwort Polygala mossii Polygala myrtifolia – butterfly-bush, myrtle-leaf milkwort, cascade curse, augustusbos Polygala nana – candyroot Polygala nicaeensis – Nice milkwort Polygala nitida – shining milkwort Polygala nudata – smallflower milkwort Polygala nuttallii – Nuttall's milkwort Polygala obscura – velvetseed milkwort Polygala ohlendorfiana Polygala oppositifolia Polygala ovatifolia – eggleaf milkwort Polygala palmeri – Palmer's milkwort Polygala paniculata – island snakeroot, ipecacuana, hoja de higo Polygala paucifolia – fringed milkwort, gaywings Polygala penaea – crevajosa Polygala persicariifolia Polygala piliophora – Huachuca Mountain milkwort Polygala planellasii – Planellas' polygala Polygala poaya – syn.
Polygala angulata Polygala polifolia Polygala polygama – racemed milkwort Polygala pottebergensis Polygala pungens – doringertjie Polygala quitensis Polygala ramosa – low pinebarren milkwort Polygala rectipilis – New Mexico milkwort Polygala rehmannii – bolao-bo-boholo Polygala rimulicola – Steyermark's milkwort Polygala rugelii – yellow milkwort Polygala rusbyi – Rusby's milkwort Polygala sanguinea – purple milkwort, blood milkwort, field milkwort Polygala scabra Polygala scoparioides – broom milkwort Polygala sekhukhuniensis Polygala senega – Seneca snakeroot, senega Polygala serpentaria – kafferslangwortel Polygala serpyllifolia – thyme-leaved milkwort Polygala setacea – coastal plain milkwort Polygala sibirica – Siberian polygala Polygala sinisica Polygala smallii – tiny milkwort Polygala subspinosa – spiny milkwort Polygala succulenta Polygala tatarinowii Polygala tenuifolia – Chinese senega-root, yuan zhi Polygala tepperi Polygala teretifolia – bothase
The Fabales are an order of flowering plants included in the rosid group of the eudicots in the Angiosperm Phylogeny Group II classification system. In the APG II circumscription, this order includes the families Fabaceae or legumes, Polygalaceae or milkworts, Surianaceae. Under the Cronquist system and some other plant classification systems, the order Fabales contains only the family Fabaceae. In the classification system of Dahlgren the Fabales were in the superorder Fabiflorae with three familiese corresponding to the subfamilies of Fabaceae in APG II; the other families treated in the Fabales by the APG II classification were placed in separate orders by Cronquist, the Polygalaceae within its own order, the Polygalales, the Quillajaceae and Surianaceae within the Rosales. The Fabaceae, as the third-largest plant family in the world, contain most of the diversity of the Fabales, the other families making up a comparatively small portion of the order's diversity. Research in the order is focused on the Fabaceae, due in part to its great biological diversity, to its importance as food plants.
The Polygalaceae are well researched among plant families, in part due to the large diversity of the genus Polygala, other members of the family being food plants for various Lepidoptera species. While taxonomists using molecular phylogenetic techniques find strong support for the order, questions remain about the morphological relationships of the Quillajaceae and Surianaceae to the rest of the order, due in part to limited research on these families; the Fabales are a cosmopolitan order of plants, except only the subfamily Papilionoideae of the Fabaceae are well dispersed throughout the northern part of the North Temperate Zone