Euphorbia milii, the crown of thorns, Christ plant, or Christ thorn, called Corona de Cristo in Latin America, is a species of flowering plant in the spurge family Euphorbiaciae, native to Madagascar. The species name commemorates Baron Milius, once Governor of Réunion, who introduced the species to France in 1821, it is suspected that the species was introduced to the Middle East in ancient times, legend associates it with the crown of thorns worn by Christ. It is a succulent shrub growing to 1.8 m tall, with densely spiny stems. The straight, slender spines, up to 3 cm long, help; the leaves are found on new growth, are up to 3.5 cm long and 1.5 cm broad. The flowers are small, subtended by a pair of conspicuous petal-like bracts, variably red, pink or white, up to 12 mm broad; the sap is moderately poisonous, causes irritation on contact with skin or eyes. If ingested, it causes severe stomach pain, irritation of the throat and mouth, vomiting; the poisonous ingredients have been identified as phorbol esters.
Wat Phrik in Thailand claims to be the home of the world's tallest Christ thorn plant. Euphorbia milii can be propagated from cuttings. E. milii is a variable species, several varieties have been described. E. milii var. splendens is considered to be the living embodiment of the supreme deity in Bathouism, a minority religion practiced by the Bodo people of Eastern India and Nepal. Euphorbia milii var. bevilaniensis Ursch & Leandri 1955 Euphorbia milii var. hislopii Ursch & Leandri 1955 Euphorbia milii var. imperatae Ursch & Leandri 1955 Euphorbia milii var. longifolia Rauh 1967 Euphorbia milii var. milii Euphorbia milii var. roseana Marn.-Lap. 1962 Euphorbia milii var. splendens Ursch & Leandri 1955 Euphorbia milii var. tananarivae Ursch & Leandri 1955 Euphorbia milii var. tenuispina Rauh & Razaf. 1991 Euphorbia milii var. tulearensis Ursch & Leandri 1955 Euphorbia milii var. vulcanii Ursch & Leandri 1955 E. milii is not hardy, does not tolerate temperatures below 10 °C. In temperate areas it needs to be grown under glass in full sun.
During the summer it may be placed outside in a sheltered spot. The speciesand the variety E. milii var. splendens have both gained the Royal Horticultural Society’s Award of Garden Merit
Pseudotsuga is a genus of evergreen coniferous trees in the family Pinaceae. Common names include Douglas fir, Douglas-fir, Douglas tree, Oregon pine. Pseudotsuga menziesii is an important source of timber; the number of species has long been debated, but two in western North America and two to four in eastern Asia are acknowledged. Nineteenth-century botanists had problems in classifying Douglas-firs, due to the species' similarity to various other conifers better known at the time; because of their distinctive cones, Douglas-firs were placed in the new genus Pseudotsuga by the French botanist Carrière in 1867. The genus name has been hyphenated as Pseudo-tsuga; the tree takes its English name from David Douglas, the Scottish botanist who first introduced Pseudotsuga menziesii into cultivation at Scone Palace in 1827. Douglas is known for introducing many native American tree species to Europe; the hyphenated form "Douglas-fir" is used by some to indicate that Pseudotsuga species are not true firs, which belong to the genus Abies.
Douglas-firs are medium-size to large evergreen trees, 20–120 metres tall. The leaves are flat, linear, 2–4 centimetres long resembling those of the firs, occurring singly rather than in fascicles; the female cones are pendulous, with persistent scales, are distinctive in having a long tridentine bract that protrudes prominently above each scale. Pseudotsuga menziesii var. menziesii has attained heights of 393 feet. That was the estimated height of the tallest conifer well-documented, the Mineral Tree, measured in 1924 by Dr. Richard E. McArdle, former chief of the U. S. Forest Service; the volume of that tree was 515 cubic metres. The tallest living individual is the Brummitt Fir in Oregon, 99.4 metres tall. Only coast redwood and Eucalyptus regnans reach greater heights based on current knowledge of living trees. At Quinault, Washington, is found a collection of the largest Douglas-firs in one area. Quinault Rain Forest hosts the most of the top ten known largest Douglas-firs; as of 2009, the largest known Douglas-firs in the world are, by volume: Red Creek Tree 12,320 cubic feet Queets Fir 11,710 cubic feet Tichipawa 10,870 cubic feet Rex 10,200 cubic feet Ol' Jed 10,040 cubic feet By far the best-known is the widespread and abundant North American species Pseudotsuga menziesii, a taxonomically complex species divided into two major varieties: coast Douglas-fir or "green Douglas-fir", on the Pacific coast.
According to some botanists, Rocky Mountain Douglas-fir extends south into Mexico to include all Mexican Douglas-fir populations, whereas others have proposed multiple separate species in Mexico and multiple varieties in the United States. Morphological and genetic evidence suggest that Mexican Douglas-fir should be considered a distinct variety within P. menziesii. All of the other species are of restricted range and little-known outside of their respective native environments, where they are rare and of scattered occurrence in mixed forests; the taxonomy of the Asian Douglas-firs continues to be disputed, but the most recent taxonomic treatment accepts four species: three Chinese and one Japanese. The three Chinese species have been variously considered varieties of P. sinensis or broken down into additional species and varieties. In the current treatment, the Chinese species P. sinensis is further subdivided into two varieties: var. sinensis and var. wilsoniana. Pseudotsuga macrocarpa Mayr – bigcone Douglas-fir - southern California Pseudotsuga menziesii Franco - western North America from Alaska to Oaxaca Pseudotsuga menziesii var. glauca Franco – Rocky Mountain Douglas-fir Pseudotsuga menziesii var. menziesii – coast Douglas-fir Pseudotsuga lindleyana Carrière – Mexican Douglas-fir Pseudotsuga brevifolia W.
C. Cheng & L. K. Fu – short-leaf Chinese Douglas-fir Pseudotsuga forrestii Craib – Yunnan Douglas-fir Pseudotsuga japonica Beissn. – Japanese Douglas-fir Pseudotsuga sinensis Dode – Chinese Douglas-fir Pseudotsuga sinensis var. sinensis Pseudotsuga sinensis var. wilsoniana – Taiwan Douglas-fir Keteleeria davidiana Beissn. Cathaya argyrophylla Keteleeria fortunei Abies magnifica Abies procera Douglas-fir wood is used for structural applications that are required to withstand high loads, it is used extensively in the construction industry. Other examples include its use for homebuilt aircraft such as the RJ.03 IBIS canard. These aircraft were designed to utilize Sitka spruce, becoming difficult to source in aviation quality grades. Oregon pine is used in boat building when it is available in long knot-free lengths. Most timber now comes from plantation forests in
Apiaceae or Umbelliferae is a family of aromatic flowering plants named after the type genus Apium and known as the celery, carrot or parsley family, or as umbellifers. It is the 16th-largest family of flowering plants, with more than 3,700 species in 434 genera including such well-known and economically important plants such as ajwain, anise, caraway, celery, coriander, dill, hemlock, cow parsley, parsley and sea holly, as well as silphium, a plant whose identity is unclear and which may be extinct; the family Apiaceae includes a significant number of phototoxic species and a smaller number of poisonous species. Some species in the family Apiaceae are cytotoxic. Most Apiaceae are annual, biennial or perennial herbs, though a minority are woody shrubs or small trees such as Bupleurum fruticosum, their leaves are of variable size and alternately arranged, or with the upper leaves becoming nearly opposite. The leaves may be sessile. There are no stipules but the petioles are sheathing and the leaves may be perfoliate.
The leaf blade is dissected, ternate or pinnatifid, but simple and entire in some genera, e.g. Bupleurum, their leaves emit a marked smell when crushed, aromatic to foetid, but absent in some species. The defining characteristic of this family is the inflorescence, the flowers nearly always aggregated in terminal umbels, that may be simple or more compound umbelliform cymes; the flowers are perfect and actinomorphic, but there may be zygomorphic flowers at the edge of the umbel, as in carrot and coriander, with petals of unequal size, the ones pointing outward from the umbel larger than the ones pointing inward. Some are andromonoecious, polygamomonoecious, or dioecious, with a distinct calyx and corolla, but the calyx is highly reduced, to the point of being undetectable in many species, while the corolla can be white, pink or purple; the flowers are nearly pentamerous, with five petals and stamens. The androecium consists of five stamens, but there is variation in the functionality of the stamens within a single inflorescence.
Some flowers are functionally staminate. Pollination of one flower by the pollen of a different flower of the same plant is common; the gynoecium consists of two carpels fused into a single, bicarpellate pistil with an inferior ovary. Stylopodia support two styles and secrete nectar, attracting pollinators like flies, gnats, beetles and bees; the fruit is a schizocarp consisting of two fused carpels that separate at maturity into two mericarps, each containing a single seed. The fruits of many species are dispersed by wind but others such as those of Daucus spp. are covered in bristles, which may be hooked in sanicle Sanicula europaea and thus catch in the fur of animals. The seeds have an oily endosperm and contain essential oils, containing aromatic compounds that are responsible for the flavour of commercially important umbelliferous seed such as anise and coriander; the shape and details of the ornamentation of the ripe fruits are important for identification to species level. Apiaceae was first described by John Lindley in 1836.
The name is derived from the type genus Apium, used by Pliny the Elder circa 50 AD for a celery-like plant. The alternative name for the family, derives from the inflorescence being in the form of a compound umbel; the family was one of the first to be recognized as a distinct group in Jacques Daleschamps' 1586 Historia generalis plantarum. With Robert Morison's 1672 Plantarum umbelliferarum distribution nova it became the first group of plants for which a systematic study was published; the family is solidly placed within the Apiales order in the APG III system. It is related to Araliaceae and the boundaries between these families remain unclear. Traditionally groups within the family have been delimited based on fruit morphology, the results from this have not been congruent with the more recent molecular phylogenetic analyses; the subfamilial and tribal classification for the family is in a state of flux, with many of the groups being found to be grossly paraphyletic or polyphyletic. According to the Angiosperm Phylogeny Website as of July 2014, 434 genera are in the family Apiaceae.
The black swallowtail butterfly, Papilio polyxenes, uses the family Apiaceae for food and host plants for oviposition. The 22-spot ladybird is commonly found eating mildew on these shrubs. Many members of this family are cultivated for various purposes. Parsnip and Hamburg parsley produce tap roots that are large enough to be useful as food. Many species produce essential oils in their leaves or fruits and as a result are flavourful aromatic herbs. Examples are parsley, coriander and dill; the seeds may be used in cuisine, as with coriander, fennel and caraway. Other notable cultivated Apiaceae include chervil, celery, sea holly, galbanum, anise, and
Crocus is a genus of flowering plants in the iris family comprising 90 species of perennials growing from corms. Many are cultivated for their flowers appearing in winter, or spring; the spice saffron is obtained from the stigmas of an autumn-blooming species. Crocuses are native to woodland and meadows from sea level to alpine tundra in central and southern Europe, in particular Krokos, Greece, on the islands of the Aegean, North Africa and the Middle East, across Central Asia to Xinjiang Province in western China; the name of the genus is derived from the Greek κρόκος. This, in turn, is a loan word from a Semitic language, related to Hebrew כרכום karkōm, Aramaic ܟܟܘܪܟܟܡܡܐ kurkama, Arabic كركم kurkum, which mean "saffron", "saffron yellow" or turmeric; the word traces back to the Sanskrit kunkumam for "saffron". The English name is a learned 16th-century adoption from the Latin, but Old English had croh "saffron". Cultivation and harvesting of Crocus sativus for saffron was first documented in the Mediterranean, notably on the island of Crete.
Frescos showing them are found at the Knossos site on Crete, as well as from the comparably aged Akrotiri site on Santorini. The first crocus seen in the Netherlands, where crocus species are not native, were from corms brought back in the 1560s from Constantinople by the Holy Roman Emperor's ambassador to the Sublime Porte, Ogier Ghiselin de Busbecq. A few corms were forwarded to Carolus Clusius at the botanical garden in Leiden. By 1620, the approximate date of Ambrosius Bosschaert's painting, new garden varieties had been developed, such as the cream-colored crocus feathered with bronze at the base of the bouquet, similar to varieties still on the market. Bosschaert, working from a preparatory drawing to paint his composed piece spanning the whole of spring, exaggerated the crocus so that it passes for a tulip, but its narrow, grass-like leaves give it away; the cup-shaped, salverform flower tapers off into a narrow tube. Their colors vary enormously, although lilac, mauve and white are predominant.
The grass-like, ensiform leaf shows a white central stripe along the leaf axis. The leaf margin is entire. A crocus has three stamens, while a similar-looking toxic plant, sometimes popularly referred to as "autumn crocus", has six stamens. In addition, crocus have one style. Crocuses are distributed across central and southern Europe, North Africa, Middle East, Central Asia to western China; the taxonomic classification proposed by Brian Mathew in 1982 was based on three character states: the presence or absence of a prophyll. The seven species discovered since have been integrated into this classification. Molecular analysis carried out at the University of Copenhagen suggests this classification should be reviewed. In particular, the DNA data suggest there are no grounds for isolating C. banaticus in its own subgenus Crociris, though it is a unique species in the genus. Because it has a prophyll at the base of the pedicel, it therefore would fall within section Crocus, although its exact relationship to the rest of the subgenus remains unclear.
Another anomalous species, C. baytopiorum, should now be placed in a series of its own, series Baytopi. C. gargaricus subsp. Herbertii has been raised as C. herbertii. Most autumn-flowering C. longiflorus, the type species of series Longiflori, now seems to lie within series Verni. In addition, the position of C. malyi is unclear. DNA analysis and morphological studies suggest further that series Reticulati and Speciosi are "probably inseparable". C. adanensis and C. caspius should be removed from Biflori. The study shows "no support for a system of sections as defined", despite the many inconsistencies between Mathew's 1982 classification and the current hypothesis, "the main assignment of species to the sections and series of that system is supported"; the authors state, "further studies are required before any firm decisions about a hierarchical system of classification can be considered" and conclude "future re-classification is to involve all infrageneric levels, subgenera and series". Below is the classification proposed by Brian Mathew in 1982, adapted in accordance with the above findings: A.
Section Crocus: species with a basal prophyllSeries Verni: corms with reticulated fibers, spring-flowering, flowers for the most part without conspicuous outer striping, bracts absent Crocus etruscus Parl. Crocus ilvensis Carta Crocus kosaninii Pulevic Crocus longiflorus Raf. – Italian crocus Crocus tommasinianus Herb. – Woodland crocus, Tommasini's crocus Crocus vernus Hill – Spring crocus, Dutch crocus Crocus vernus subsp. Albiflorus Asch. & Graebn. Crocus vernus subsp. VernusSeries Baytopi: corms with reticulated fibers. Series Versicolores: spring-flowering, corms with tunics, which for the most part have parallel fibers, flowers with conspicuous exterior striping Crocus cam
Botany called plant science, plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist; the term "botany" comes from the Ancient Greek word βοτάνη meaning "pasture", "grass", or "fodder". Traditionally, botany has included the study of fungi and algae by mycologists and phycologists with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists study 410,000 species of land plants of which some 391,000 species are vascular plants, 20,000 are bryophytes. Botany originated in prehistory as herbalism with the efforts of early humans to identify – and cultivate – edible and poisonous plants, making it one of the oldest branches of science. Medieval physic gardens attached to monasteries, contained plants of medical importance, 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. These gardens facilitated the academic study of plants. Efforts to catalogue and describe their collections were the beginnings of plant taxonomy, led in 1753 to the binomial system of Carl Linnaeus that remains in use to this day. In the 19th and 20th centuries, new techniques were developed for the study of plants, including methods of optical microscopy and live cell imaging, electron microscopy, analysis of chromosome number, plant chemistry and the structure and function of enzymes and other proteins. 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 and technology. Research topics include the study of plant structure and differentiation, reproduction and primary metabolism, chemical products, diseases, evolutionary relationships and plant taxonomy.
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. Botanical research has diverse applications in providing staple foods, materials such as timber, rubber and drugs, in modern horticulture and forestry, plant propagation and genetic modification, in the synthesis of chemicals and raw materials for construction and energy production, in environmental management, the maintenance of biodiversity. Botany originated as 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, which make up much of the Cherokee land today. The early recorded history of botany includes many ancient writings and plant classifications. Examples of early botanical works have been found in ancient texts from India dating back to before 1100 BC, in archaic Avestan writings, in works from China before it was unified in 221 BC.
Modern botany traces its roots back to Ancient Greece to Theophrastus, a student of Aristotle who invented and described many of its principles and is regarded in the scientific community as the "Father of Botany". His major works, Enquiry into Plants and On the Causes of Plants, constitute the most important contributions to botanical science until the Middle Ages seventeen centuries later. Another work from Ancient Greece that made an early impact on botany is De Materia Medica, a five-volume encyclopedia about herbal medicine written in the middle of the first century by Greek physician and pharmacologist Pedanius Dioscorides. De Materia Medica was read for more than 1,500 years. Important contributions from the medieval Muslim world include Ibn Wahshiyya's Nabatean Agriculture, Abū Ḥanīfa Dīnawarī's the Book of Plants, Ibn Bassal's The Classification of Soils. In the early 13th century, Abu al-Abbas al-Nabati, Ibn al-Baitar wrote on botany in a systematic and scientific manner. In the mid-16th century, "botanical gardens" were founded in a number of Italian universities – the Padua botanical garden in 1545 is considered to be the first, still in its original location.
These gardens continued the practical value of earlier "physic gardens" 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 to northern Europe. Throughout this period, botany remained 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
Cornus is a genus of about 30–60 species of woody plants in the family Cornaceae known as dogwoods, which can be distinguished by their blossoms and distinctive bark. Most are deciduous trees or shrubs, but a few species are nearly herbaceous perennial subshrubs, a few of the woody species are evergreen. Several species have small heads of inconspicuous flowers surrounded by an involucre of large white petal-like bracts, while others have more open clusters of petal-bearing flowers; the various species of dogwood are native throughout much of temperate and boreal Eurasia and North America, with China and Japan and the southeastern United States rich in native species. Species include the common dogwood Cornus sanguinea of Eurasia, the cultivated flowering dogwood of eastern North America, the Pacific dogwood Cornus nuttallii of western North America, the Kousa dogwood Cornus kousa of eastern Asia, two low-growing boreal species, the Canadian and Eurasian dwarf cornels, Cornus canadensis and Cornus suecica respectively.
Depending on botanical interpretation, the dogwoods are variously divided into one to nine genera or subgenera. The name "dog-tree" entered the English vocabulary before 1548, becoming "dogwood" by 1614. Once the name dogwood was affixed to this kind of tree, it soon acquired a secondary name as the Hound's Tree, while the fruits came to be known as dogberries or houndberries. Another theory advances the view that "dogwood" was derived from the Old English dagwood, from the use of the slender stems of its hard wood for making "dags". Another, earlier name of the dogwood in English is the whipple-tree. Geoffrey Chaucer uses "whippletree" in The Canterbury Tales to refer to the dogwood. A whippletree is an element of the traction of a horse-drawn cart, linking the drawpole of the cart to the harnesses of the horses in file. Dogwoods have simple, untoothed leaves with the veins curving distinctively as they approach the leaf margins. Most dogwood species have opposite leaves, while a few, such as Cornus alternifolia and C. controversa, have their leaves alternate.
Dogwood flowers have four parts. In many species, the flowers are borne separately in open clusters, while in various other species, the flowers themselves are clustered, lacking showy petals, but surrounded by four to six large white petal-like bracts; the fruits of all dogwood species are drupes with one or two seeds brightly colorful. The drupes of species in the subgenera Cornus are edible. Many are without much flavor. Cornus kousa and Cornus mas are sold commercially as edible fruit trees; the fruits of Cornus kousa have a tropical pudding like flavor in addition to hard pits. The fruits of Cornus mas are both tart and sweet when ripe, they have been eaten in Eastern Europe for centuries, both as food and medicine to fight colds and flus. They are high in vitamin C. However, those of species in subgenus Swida are mildly toxic to people, though eaten by birds. Dogwoods are used as food plants by the larvae of some species of butterflies and moths, including the emperor moth, the engrailed, the small angle shades, the following case-bearers of the genus Coleophora: C. ahenella, C. salicivorella, C. albiantennaella, C. cornella and C. cornivorella, with the latter three all feeding on Cornus.
Dogwoods are planted horticulturally, the dense wood of the larger-stemmed species is valued for certain specialized purposes. Cutting boards and other fine turnings can be made from this fine beautiful wood. Over 32 different varieties of game birds, including quail, feed on the red seeds. Various species of Cornus the flowering dogwood, are ubiquitous in American gardens and landscaping. S. except the hottest and driest areas". In contrast, in England the lack of sharp winters and hot summers makes Cornus florida shy of flowering. Other Cornus species are stoloniferous shrubs that grow in wet habitats and along waterways. Several of these are used along highways and in naturalizing landscape plantings those species with bright red or bright yellow stems conspicuous in winter, such as Cornus stolonifera; the following cultivars, of mixed or uncertain origin, have gained the Royal Horticultural Society’s Award of Garden Merit: ‘Eddie’s White Wonder’ ‘Norman Hadden’ ‘Ormonde’ ‘Porlock’ The species Cornus mas is cultivated in southeastern Europe for its showy, edible berries, that have the color of the carnelian gemstone.
Cornelian-cherries are used in syrups and preserves. Dense and fine-grained, dogwood timber has a density of 0.79 and is prized for making loom shuttles, tool handles, roller skates and other small items that require a hard and strong wood. Though it is tough for woodworking, some artisans favor dogwood for small projects such as walking canes, arrow making, mountain dulcimers and fine inlays. Dogwood wood is an excellent substitute for persimmon wood in the heads of certain golf clubs. Dogwood lumber is rare in that it is not available with any manufacturer and must be cut down by the person wanting to use it. Larger items have been made of dogwood, such as the screw-in basket-style
An inflorescence is a group or cluster of flowers arranged on a stem, composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants; the modifications can involve the length and the nature of the internodes and the phyllotaxis, as well as variations in the proportions, swellings, adnations and reduction of main and secondary axes. Inflorescence can be defined as the reproductive portion of a plant that bears a cluster of flowers in a specific pattern; the stem holding the whole inflorescence is called a peduncle and the major axis holding the flowers or more branches within the inflorescence is called the rachis. The stalk of each single flower is called a pedicel. A flower, not part of an inflorescence is called a solitary flower and its stalk is referred to as a peduncle. Any flower in an inflorescence may be referred to as a floret when the individual flowers are small and borne in a tight cluster, such as in a pseudanthium.
The fruiting stage of an inflorescence is known as an infructescence. Inflorescences may be complex; the rachis may be one of several types, including single, umbel, spike or raceme. Inflorescences are described by many different characteristics including how the flowers are arranged on the peduncle, the blooming order of the flowers and how different clusters of flowers are grouped within it; these terms are general representations. Inflorescences have modified shoots foliage different from the vegetative part of the plant. Considering the broadest meaning of the term, any leaf associated with an inflorescence is called a bract. A bract is located at the node where the main stem of the inflorescence forms, joined to the main stem of the plant, but other bracts can exist within the inflorescence itself, they serve a variety of functions which include protecting young flowers. According to the presence or absence of bracts and their characteristics we can distinguish: Ebracteate inflorescences: No bracts in the inflorescence.
Bracteate inflorescences: The bracts in the inflorescence are specialised, sometimes reduced to small scales, divided or dissected. Leafy inflorescences: Though reduced in size, the bracts are unspecialised and look like the typical leaves of the plant, so that the term flowering stem is applied instead of inflorescence; this use is not technically correct, as, despite their'normal' appearance, these leaves are considered, in fact, bracts, so that'leafy inflorescence' is preferable. Leafy-bracted inflorescences: Intermediate between bracteate and leafy inflorescence. If many bracts are present and they are connected to the stem, like in the family Asteraceae, the bracts might collectively be called an involucre. If the inflorescence has a second unit of bracts further up the stem, they might be called an involucel. Plant organs can grow according to two different schemes, namely monopodial or racemose and sympodial or cymose. In inflorescences these two different growth patterns are called indeterminate and determinate and indicate whether a terminal flower is formed and where flowering starts within the inflorescence.
Indeterminate inflorescence: Monopodial growth. The terminal bud keeps forming lateral flowers. A terminal flower is never formed. Determinate inflorescence: Sympodial growth; the terminal bud forms a terminal flower and dies out. Other flowers grow from lateral buds. Indeterminate and determinate inflorescences are sometimes referred to as open and closed inflorescences respectively; the indeterminate patterning of flowers is derived from determinate flowers. It is suggested that indeterminate flowers have a common mechanism that prevents terminal flower growth. Based on phylogenetic analyses, this mechanism arose independently multiple times in different species. In an indeterminate inflorescence there is no true terminal flower and the stem has a rudimentary end. In many cases the last true flower formed by the terminal bud straightens up, appearing to be a terminal flower. A vestige of the terminal bud may be noticed higher on the stem. In determinate inflorescences the terminal flower is the first to mature, while the others tend to mature starting from the bottom of the stem.
This pattern is called acropetal maturation. When flowers start to mature from the top of the stem, maturation is basipetal, while when the central mature first, divergent; as with leaves, flowers can be arranged on the stem according to many different patterns. See'Phyllotaxis' for in-depth descriptions Similarly arrangement of leaf in bud is called Ptyxis. Metatopy is the placement of organs out of their expected position: metatopy occurs in inflorescences when unequal growth rates alter different areas of the axis and the organs attached to the axis; when a single or a cluster of flower is located at the axil of a bract, the location of the bract in relation to the stem holding the flower is indicated by the use of different terms and may be a useful diagnostic indicator. Typical placement of bracts include: Some plants have bracts that subtend the inflorescence, where the flowers are on branched stalks.