This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnifying lens. This page provides help in understanding the numerous other pages describing plants by their various taxa. The accompanying page—Plant morphology—provides an overview of the science of the external form of plants. There is also an alphabetical list: Glossary of botanical terms. In contrast, this page deals with botanical terms in a systematic manner, with some illustrations, and organized by plant anatomy and function in plant physiology.
This glossary primarily includes terms that deal with vascular plants (ferns, gymnosperms and angiosperms), particularly flowering plants (angiosperms). Non-vascular plants (bryophytes), with their different evolutionary background, tend to have separate terminology. Although plant morphology (the external form) is integrated with plant anatomy (the internal form), the former became the basis of the taxonomic description of plants that exists today, due to the few tools required to observe.
Many of these terms date back to the earliest herbalists and botanists, including Theophrastus. Thus, they usually have Greek or Latin roots. These terms have been modified and added to over the years, and different authorities may not always use them the same way.
This page has two parts: The first deals with general plant terms, and the second with specific plant structures or parts.
General plant terms
Abaxial – located on the side facing away from the axis.
Adaxial – located on the side facing towards the axis.
Striated – marked by a series of lines, grooves, or ridges
Tesselate – marked by a pattern of polygons, usually rectangles
Wing (plant) – any flat surfaced structure emerging from the side or summit of an organ; seeds, stems.
Plant habit refers to the overall shape of a plant, and it describes a number of components such as stem length and development, branching pattern, and texture. While many plants fit neatly into some main categories, such as grasses, vines, shrubs, or trees, others can be more difficult to categorise. The habit of a plant provides important information about its ecology: that is, how it has adapted to its environment. Each habit indicates a different adaptive strategy. Habit is also associated with the development of the plant. As such, it may change as the plant grows and is more properly called its growth habit. In addition to shape, habit indicates plant structure; for instance, whether the plant is herbaceous or woody.
Each plant commences its growth as a herbaceous plant. Plants that remain herbaceous are shorter and seasonal, dying back at the end of their growth season. Woody plants (such as trees, shrubs and woody vines (lianas) will gradually acquire woody (lignaceous) tissues, which provide strength and protection for the vascular system, and they tend to be tall and relatively long lived. The formation of woody tissue is an example of secondary growth, a change in existing tissues, in contrast to primary growth that creates new tissues, such as the elongating tip of a plant shoot. The process of wood formation (lignification) is commonest in the Spermatophytes (seed bearing plants) and has evolved independently a number of times. The roots may also lignify, aiding in the role of supporting and anchoring tall plants, and may be part of a descriptor of the plant's habit.
Plant habit can also refer to whether the plant possesses any specialised systems for the storage of carbohydrates or water, allowing the plant to renew its growth after an unfavourable period. Where the amount of water stored is relatively high, the plant is referred to as a succulent. Such specialised plant parts may arise from the stems or roots. Examples include plants growing in unfavourable climates, very dry climates where storage is intermittent depending on climatic conditions, and those adapted to surviving fires and regrowing from the soil afterwards.
Some types of plant habit include:
Herbaceous plants (also called Herbs): A plant whose structures above the surface of the soil, vegetative or reproductive, die back at the end of the annual growing season, and never become woody. While these structures are annual in nature, the plant itself may be annual, biannual, or perennial. Herbaceous plants that survive for more than one season possess underground storage organs, and thus are referred to as geophytes.
Terms used in describing plant habit, include:
An acaulescent species of Streptocarpus has only one leaf, and appears to have no stem
Acaulescent – the leaves and inflorescence rise from the ground, and appear to have no stem. They are also known as rosette forms, some of the many conditions that result from very short internodes (i.e. close distances between nodes on the plant stem. See also radical, where leaves arise apparently without stems.
Acid plant – plants with acid saps, normally due to the production of ammonium salts (malic and oxalic acid)
Acme – the time when the plant or population has its maximum vigor.
Actinomorphic – parts of plants that are radially symmetrical in arrangement.
Arborescent – growing into a tree-like habit, normally with a single woody stem.
Ascending – growing uprightly, in an upward direction.
Angiosperms. Only the sporophyte is visible, the gametophytes being the pollen and ovule
Plant structures or organs fulfil specific functions, and those functions determine the structures that perform them. Among terrestrial (land) plants, the vascular and non-vascular plants (Bryophytes) evolved independently in terms of their adaptation to terrestrial life and are treated separately here (see Bryophytes).
Common structural elements are present in the embryonic part of the life cycle, which is the diploidmulticellular phase. The embryo develops into the sporophyte, which at maturity produces haploid spores, which germinate to produce the gametophyte, the haploid multicellular phase. The haploid gametophyte then produces gametes, which may fuse to form a diploid zygote, and finally an embryo. This phenomenon of alternating diploid and haploid multicellular phases is common to the embryophytes (land plants) and is referred to as the alternation of generations. A major difference between vascular and non-vascular plants is that in the latter the haploid gametophyte is the more visible and longer-lived stage. In vascular plants, the diploid sporophyte has evolved as the dominant and visible phase of the life cycle. In seed plants and some other groups of vascular plants the gametophyte phases are strongly reduced in size and contained within the pollen and ovules. The female gametophyte is entirely contained within the sporophyte's tissues, while the male gametophyte in its pollen grain is released and transferred by wind or animal vectors to fertilize the ovules.
Amongst the vascular plants, the structures and functions of the Pteridophyta (ferns), which reproduce seedlessly, are also sufficiently different to justify separate treatment, as here (see Pteridophytes). The remainder of the vascular plant sections address the higher plants (Spermatophytes or Seed Plants, i.e. Gymnosperms and Angiosperms or flowering plants). In the higher plants, the terrestrial sporophyte has evolved specialised parts. In essence, they have a lower, underground component and an upper, aerial component. The underground part develops roots that seek water and nourishment from the soil, while the upper component, or shoot, grows toward the light and develops a plant stem, leaves and specialised reproductive structures (sporangia). In angiosperms, the sporangia are located in the stamenanthers (microsporangia) and ovules (megasporangia). The specialised sporangia bearing stem is the flower. In angiosperms, if the female sporangium is fertilised, it becomes the fruit, a mechanism for dispersing the seeds produced from the embryo.
Thus, the terrestrial sporophyte has two growth centres, the stem growing upwards while the roots grow downwards. New growth occurs at the tips (apices) of both the shoot and roots, where the undifferentiated cells of the meristem divide. Branching occurs to form new apical meristems. Growth of the stem is indeterminate in pattern (not pre-determined to stop at a particular point). The functions of the stem are to raise and support the leaves and reproductive organs above the level of the soil, to facilitate absorption of light for photosynthesis, gas exchange, water exchange (transpiration), pollination, and seed dispersal. The stem also serves as a conduit, from roots to overhead structures, for water and other growth-enhancing substances. These conduits consist of specialised tissues known as vascular bundles, which give the name "vascular plants" to the angiosperms. The point of insertion, on the stem, of leaves or buds is a node, and the space between two successive nodes, an internode.
The leaves, which emerge from the shoot, are specialised structures that carry out photosynthesis, and gas (oxygen and carbon dioxide) and water exchange. They are sheathed by an outer layer or epidermis that is coated with a waxy waterproof protective layer, which is punctuated by specialised pores, known as stomata, which regulate gas and water exchange. The leaves also possess vascular bundles, which are generally visible as veins, whose patterns are called venation. Leaves tend to have a shorter life span than the stems or branches that bear them, and when they fall, an area at the attachment zone, called the abscission zone leaves a scar on the stem.
In the angle (adaxial) between the leaf and the stem, is the axil. Here can be found buds (axillary buds), which are miniature and often dormant branches with their own apical meristem. They are often covered by leaves.
The flower, which is one of the defining features of angiosperms, is essentially a stem whose leaf primordia become specialised, following which the apical meristem stops growing: a determinate growth pattern, in contrast to vegetative stems. The flower stem is known as a pedicel, and those flowers with such a stem are called pedicellate, while those without are called sessile. In the angiosperms, the flowers are arranged on a flower stem as an inflorescence. Just beneath (subtended) the flower there may be a modified, and usually reduced, leaf, called a bract. A secondary smaller bract is a bracteole (bractlet, prophyll, prophyllum), often on the side of the pedicel, and generally paired. A series of bracts subtending the calyx (see below) is an epicalyx. Angiosperms are dealt with in more detail here; these structures are very different in gymnosperms.
In angiosperms, the specialised leaves that play a part in reproduction are arranged around the stem in an ordered fashion, from the base to the apex of the flower. The floral parts are arranged at the end of a stem without any internodes. The receptacle (also called the floral axis, or thalamus) is generally very small. Some flower parts are solitary, while others may form a tight spiral, or whorl, around the flower stem. First, at the base, are those non-reproductive structures involved in protecting the flower when it is still a bud, the sepals, then are those parts that play a role in attracting pollinators and are typically coloured, the petals, which together with the sepals make up the perianth (perigon, perigonium). If the perianth is differentiated, the outer whorl of sepals forms the calyx, and the inner whorl of petals, the corolla. If the perianth is not differentiated into sepals and petals, they are collectively known as tepals. In some flowers, a tube or cup-like hypanthium (floral tube) is formed above or around the ovary and bears the sepals, petals, and stamens. There may also be a nectary producing nectar. Nectaries may develop on or in the perianth, receptacle, androecium (stamens), or gynoecium. In some flowers nectar may be produced on nectariferous disks. Disks may arise from the receptable and are doughnut- or disk-shaped. They may also surround the stamens (extrastaminal), be at the stamen bases (staminal), or be inside the stamina (intrastaminal).
Finally, the actual reproductive parts form the innermost layers of the flower. These leaf primordia become specialised as sporophylls, leaves that form areas called sporangia, which produce spores, and cavitate internally. The sporangia on the sporophytes of pteridophytes are visible, but those of gymnosperms and angiosperms are not. In the angiosperms there are two types. Some form male organs (stamens), the male sporangia (microsporangia) producing microspores. Others form female organs (carpels), the female sporangia (megasporangia) producing a single large megaspore. These in turn produce the male gametophytes and female gametophytes
These two components are the androecium and gynoecium, respectively. The Androecium (literally, men's house) is a collective term for the male organs (stamens or microsporophylls). While sometimes leaflike (laminar), more commonly they consist of a long thread-like column, the filament, surmounted by a pollen bearing anther. The anther usually consists of two fused thecae. A theca is two microspoorangia. The gynoecium (women's house) is the collective term for the female organs (carpels). A carpel is a modified megasporophyll consisting of two or more ovules, which develop conduplicatively (folded along the line). The carpels may be single, or collected together, to form an ovary, and contain the ovules. Another term, pistil, refers to the ovary as its expanded base, the style, a column arising from the ovary, and an expanded tip, the stigma.
Within the stamen, the microsporangium forms grains of pollen, surrounded by a protective microspore, which form the male gametophyte. Within the carpel the megasporangium form the ovules, with its protective layers (integument) in the megaspore, and the female gametophyte. Unlike the male gametophyte, which is transported in the pollen, the female gametophyte remains within the ovule.
Most flowers have both male and female organs, and hence are considered bisexual (perfect), which is thought to be the ancestral state. However, others have either one or the other and are therefore unisexual, or imperfect. In which case they may be either male (staminate) or female (pistillate). Plants may bear either all bisexual flowers (hermaphroditic), both male and female flowers (monoecious), or only one sex (dioecious), in which case separate plants are either male or female flower-bearing. Where both bisexual and unisexual flowers exist on the same plant, it is called polygamous. Polygamous plants may have bisexual and staminate flowers (andromonoecious), bisexual and pistillate flowers (gynomonoecious), or both (trimonoecious). Other combinations include the presence of bisexual flowers on some individual plants and staminate on others (androdioecious), or bisexual and pistillate (gynodioecious). Finally, trioecious plants have bisexual, staminate, or pistillate flowers on different individuals. Arrangements other than hermaphroditic help to ensure outcrossing.
The development of the embryo and gametophytes is called embryology. The study of pollens which persist in soil for many years is called palynology. Reproduction occurs when male and female gametophytes interact. This generally requires an external agent such as wind or insects to carry the pollen from the stamen to the vicinity of the ovule. This process is called pollination. In gymnosperms (literally naked seed) pollen comes into direct contact with the exposed ovule. In angiosperms the ovule is enclosed in the carpel, requiring a specialised structure, the stigma, to receive the pollen. On the surface of the stigma, the pollen germinates; that is, the male gametophyte penetrates the pollen wall into the stigma, and a pollen tube, an extension of the pollen grain, extends towards the carpel, carrying with it the sperm cells (male gametes) until they encounter the ovule, where they gain access through a pore in the ovule's integument (micropyle), allowing fertilisation to occur. Once the ovule has been fertilised, a new sporophyte, protected and nurtured by the female gametophyte, develops and becomes an embryo. When development stops, the embryo becomes dormant, as a seed. Within the embryo are the primordial shoot and root.
In angiosperms, as the seed develops after fertilisation, so does the surrounding carpel, its walls thickening or hardening, developing colours or nutrients that attract animals or birds. This new entity with its dormant seeds is the fruit, whose functions are protecting the seed and dispersing it. In some cases, androecium and gynaecium may be fused. The resulting structure is a gynandrium (gynostegium, gynostemium, or column), which is supported by an androgynosphore.
Ptyxis – the way in which an individual leaf is folded within an unopened bud.
Vernation – the arrangement of leaves in an unopened bud.
Plants, with regard to identification and classification, are not often characterized by their roots, which are important in determining plant duration. However, in some groups, including the grasses, roots are important for proper identification.
Adventitious – roots that form from other than the hypocotyl or from other roots. Roots forming on the stem are adventitious.
Aerial – roots growing in the air.
(Root) crown – the place where the roots and stem meet, which may or may not be clearly visible.
Fibrous – describes roots that are thread-like and normally tough.
Fleshy – describes roots that are relatively thick and soft, normally made up of storage tissue. Roots are typically long and thick but not thickly rounded in shape.
Haustorial – specialized roots that invade other plants and absorb nutrients from those plants.
Lignotuber – root tissue that allows plants to regenerate after fire or other damage.
Primary – root that develop from the radicle of the embryo, and is normally the first root to emerge from the seed as it germinates.
Root Hairs – very small roots, often one cell wide, that do most of the water and nutrient absorption.
Secondary – roots forming off of the primary root; often called branch roots.
Taproot – a primary root that more-or-less enlarges and grows downward into the soil.
Tuberous – roots that are thick and soft with storage tissue, and are typically thick and round in shape.
Epiblema – Outermost (epidermal) layer of rootlets. Normally 1-cell-layer thick (uniseriate). Normally do not have a cuticle, and permit water conduction.
Quiescent centre – a small region inside the root's apical region that has a slower division rate.
Root Cap – a cover or cap-like structure that protects the tip of root.
Multiple root caps - several layers of root caps on a single root apex; seen in Pandanus sp.
Root Pocket – a cap-like structure on the root-apex of some aquatic plants, which, unlike root-caps, doesn't reappear if removed somehow.
Root hair – fine cellular appendages from cells of epiblema. They are unicellular, which means one root hair and corresponding cell of epiblema comprise only 1 cell. By contrast, stem and leaf hairs can be unicellular or multicellular. Root hairs of older portions of roots are destroyed over time, and only at a certain region near a growing apex (called the root-hair-region) are root hairs seen. Although microscopic, root-hairs can be observed by the unaided eye in chili and Brassica seedlings.
Conical root – Storage root that is broad at its base (upper portion) and gradually tapers to its apex (lower portion): e.g., Carrot.
Fusiform root – Storage root that is swollen in the centre and tapers towards both apex and base: e.g., radish (Raphanus sativus).
Napiform root – Root whose upper (basal) portion is heavily swollen but whose lower (apical) portion is narrow and tapering: e.g., beet, turnip.
Tuberous or tubercular tap-root – In its narrow sense, a tap-root that is thick and fleshy (due to storage) but that does not conform to the fusiform, conical, napiform shape: Mirabilis jalapa. In its broader sense, a tap-root that is thick and fleshy (due to storage); i.e. when tuberation take place in a tap-root.
Pneumatophores (respiratory roots) – Part of tap-root system as respiratory roots; found in many mangrove trees. They arise from the thick, mature branches of tap-root systems, and grow upwards. The inner tissue of respiratory roots is full of hollow, airy, tube-like dead cells, giving it a spongy texture. The outer surface of pneumatophores contains tiny pores or openings, which are called pneumathodes: e.g., Heritiera fomes, Rhizophora mucronata. Pneumatophores can be unbranched or sparingly branched.
Vivipary – This is a feature of many mangrove trees, where the seed germinates when the seed (and fruit) remain joined to the mother plant until the radicle and hypocotyl grow, reach the ground, and establish there.
(See also: seeds and germination related sections and articles)
Adventitious root systems
Fibrous root – Originate from the base of a young stem and replace the primary root (and also from the stem nodes, and sometimes internodes), and emanate as a parallel cluster or bunch from around the node. The adventitious roots of monocots are usually of this type. Replacement of a tap root system by a fibrous root is seen in onions, tuberose (Polyanthes tuberosa), grasses, etc. Fibrous roots from normal-stem nodes are seen in grasses like maize, sugarcane, bamboo, etc. Fibrous roots from nodes help in the survival of the plant and thus in vegetative reproduction, when the plant's base is damaged or cut inside the stem axis.
Many dicots, too, release adventitious toots from stem-nodes, especially those that can regenerate vegetatively (Hibiscus rosa-sinensis, Coleus, etc.) and those that have a week stem with creeping habit (Centella asiatica, Bacopa monnieri, etc.). These roots are called adventitious, not fibrous, roots.
Adventitious storage roots – similar function as storage-taproots.
Tuberous roots or root tubers – Narrow sense, those storage roots that do not conform to a specific shape, such as fasciculated, nodulose moniliform, annulated, etc.: e.g. sweet potato (Ipomoea batatas), whose edible part is a root of this type. Broader sense, adventitious roots swollen due to their storage function.
Fasciculated root – When several tubercular roots grow as a parallel bunch or bundle. Seen in Dahlia sp., Ruellia tuberosa, Asparagus racemosus, etc. Orchis maculata have a pair of bulbous storage-roots.
Nodulose root – Not to be confused with root-nodules. Storage pattern is a root axis swollen near the apical portion, thus forming a bulbous or tuberous structure at or near the root tip. It is commonly seen associated with a rhizomatous stem. It is seen in Costus speciosus,Curcuma amada,Curcuma domestica, Asparagus sprengeri, Arrowroot (Maranta), etc. and some species of Calathea.
Moniliform or Beaded root – When more than one swelling, or nodule-like, structures occur at intervals along the root axis. Such an alternating swollen-and-constricted pattern is seen in Cyperus sp., Dioscorea alata,Vitis trifolia, Portulaca sp., Basella sp., Momordica sp. and some grasses.
Annulated root – Like moniliform roots, annulated roots also contain alternating swollen and constricted regions; but here the length of constricted regions is so short that the root appears as a stack of discs. It is seen in Cephalis ipecacuanha (Rubiaceae).
Floating or Aquatic-respiratory root – The upright, spongy structures helps the plant to float. Seen in Jussiaea repens.
Epiphytic root – This type of root seen in epiphytic orchids. The thick root hangs from the plant's base directly into air. The root is covered with a special, usually 4- to 5-cell layer thick, spongy tissue (called Velamen), which helps the plant to absorb moisture from the atmosphere. Epiphytic orchid have another sort of root, called clinging roots, that help the orchid plant cling to the substratum (host). Since a similar function is seen in many other plants' adventitious roots, it is being mentioned in more general terms in the mechanical advancements section.
Parasitic root or Haustoria –
Assimilatory or Photosynthetic roots –
Mechanical advancements –
Prop-roots – In some dome-shaped (deliquescent) trees, from the mature horizontal boughs (stem-branches) some quite thick (millimeters to centimeters) roots come down. After growing and reaching the ground, they establish more elaborate root branches as well as show massive secondary thickening. Thus, they start to resemble the main trunk. Besides carrying the weight of horizontal boughs, when the main trunk is destroyed due to ageing or accident, the established prop-roots support the remaining plant-body, thus helping in vegetative reproduction. E.g. Ficus benghalensis. The Great Banyan Tree at IBG Kolkata is an example how prop-roots help in vegetative reproduction.
Stilt roots – From upright (erect) trunks, some hard, thick, almost straight roots come-out obliquely and penetrate the ground. Thus they act like a camera-tripod. They increase balance and support as well as, when these roots penetrates the ground, they increase soil grip.
Root-Buttress or Plank Buttress or Buttress-Root –
Reproductive roots – These roots contain root-buds and actively take part in shoot-regeneration, and thus in vegetative reproduction. This is an unusual feature because roots normally do not contain buds.
Prop roots in Ficus benghalensis in Indian Botanic Garden.
Ficus benghalensis prop roots
Stilt roots in Pandanus sp.
Stilt roots in Socratea exorrhiza palm
Stilt-roots in mangrove plants
Parts of plant stem
Euonymus alata, an example of alate stems
Saraca cauliflora, an example of cauliflora
Sciadopitys verticillata, an example of a verticillate plant
Accessory buds – an embryonic shoot occurring above or to the side of an axillary bud; also known as supernumerary bud.
Acrocarpous – produced at the end of a branch.
Acutangular – a stem that has several longitudinally running ridges with sharp edges.
Adventitious buds – a bud that arises at points on the plant other than at the stem apex or leaf axil.
Alate – having wing-like structures, usually on the seeds or stems, as in Euonymus alata.
Alternate – buds are staggered on opposite sides of the branch.
Chambered pith – a form of pith in which the parenchyma collapses or is torn during development, leaving the sclerenchyma plates to alternate with hollow zones
Diaphragmed pith – pith in which plates or nests of sclerenchyma may be interspersed with the parenchyma.
Plagiotropic growth – growth inclined away from the vertical, inclined towards the horizontal.
Prickle – an extension of the cortex and epidermis that ends with a sharp point.
Prostrate – growing flat on the soil surface.
Rhizome – a horizontally orientated, prostrate stem with reduced scale-like leaves, normally growing under ground but also on the soil surface. Also produced by some species that grow in trees or water.
Rootstock – the underground part of a plant normally referring to a caudex or rhizome.
Runner – an above-ground stem, usually rooting and producing new plants at the nodes.
Acephalous – without a head, used to describe a flower style without a well-developed stigma.
Bract – the leaf- or scale-like appendages that are located just below a flower, a flower stalk, or an inflorescence; they usually are reduced in size and sometimes showily or brightly colored.
Calyx – the whorl of sepals at the base of a flower, the outer whorl of the perianth.
Carpel – the ovule-producing reproductive organ of a flower, consisting of the stigma, style, and ovary.
Claw – a noticeably narrowed or attenuated organ base, typically a petal; e.g. Viola.
Connate – when the same parts of a flower are fused to each other, petals in a gamopetalous flower; e.g. Petunia.
Corolla – the whorl of petals of a flower.
Corona – an additional structure between the petals and the stamens.
Disk – an enlargement or outgrowth from the receptacle of the flower, located at the center of the flowers of various plants. The term is also used for the central area of the head in composites where tubular flowers are attached.
Fruit – a structure containing all the seeds produced by a single flower.
Nectar – a fluid produced by nectaries that is high in sugar content; used to attract pollinators.
Nectary – a gland that secrets nectar, most often found in flowers, but also produced on other parts of plants.
Nectar disk – when the floral disk contains nectar secreting glands; often modified as its main function in some flowers.
Pedicel – the stem or stalk that holds a single flower in an inflorescence.
Peduncle – the part of a stem that bears the entire inflorescence, normally having no leaves, or the leaves having been reduced to bracts. When the flower is solitary, it is the stem or stalk holding the flower.
Peduncular – referring to or having a peduncle.
Pedunculate – having a peduncle.
Achlamydeous – without a perianth.
Receptacle – the end of the pedicel that joins to the flower were the different parts of the flower are joined together; also called the torus. In Asteraceae, the top of the pedicel upon which the flowers are joined.
Antipetalous – when the stamens number the same as, and are arranged opposite, the corolla segments; e.g. Primula.
Antisepalouse – when the stamens number the same as, and are arranged opposite, the calyx segments.
Connective – the part of the stamen joining the anther cells.
Capitulum – the flowers are arranged into a head composed of many separate unstalked flowers, the single flowers being packed close together and called florets, which is the typical arrangement in Asteraceae.
Compound Umbel – an umbel where each stalk of the main umbel produces another smaller umbel of flowers.
Corymb – a grouping of flowers where all the flowers are at the same level, the flower stalks of different lengths forming a flat-topped flower cluster.
Cyme – is a cluster of flowers where the end of each growing point produces a flower. New growth comes from side shoots, and the oldest and first flowers to bloom are at the top.
Single – one flower per stem, or flowers greatly spread apart so as to appear to not arise from the same branch.
Spike – flowers arising from the main stem are without individual flower stalks. The flowers attach directly to the stem.
Solitary – same as single, with one flower per stem.
Raceme – a flower spike with flowers that have stalks of equal length. The stem tip continues to grow and produces more flowers, with the bottom flowers opening first and blooming progressing up the stem.
Panicle – a raceme with branches, each branch having a smaller raceme of flowers. The terminal bud of each branch continues to grow, producing more side shoots and flowers.
Pedicel – stem holding a one flower in an inflorescence.
Peduncle – stem holding an inflorescence, or a single flower.
Umbel – where the flower head has all flower stalks rising from the same point and of equal length, the flower head seeming hemispherical like an open umbrella.
Verticillaster – a whorled collection of flowers around a stem, the flowers produced in rings at intervals up the stem. As the stem tip continues to grow, more whorls of flowers are produced. Typical in Lamiaceae.
Verticil – flowers arranged in whorls at the nodes.
Fruits are the mature ovary of seed-bearing plants, and they include the contents of the ovary, which can be floral parts like the receptacle, involucre, calyx, and others that are fused to it. Fruits are often used to identify plant taxa, help to place the species in the correct family, or differentiate different groups within the same family.
Terms for fruits
Accessory structures – parts of fruits that do not form from the ovary.
Beak – normally the slender elongated end of a fruit, typically a persistent style-base.
Circumscissile – a type of fruit that dehisces, where the top of the fruit falls away like a lid or covering.
Dehiscent – a fruit that opens and releases its contents, normally in a regular and distinctive fashion.
Endocarp – includes the wall of the seed chamber, the inner part of the pericarp.
Exocarp – the pericarp's outer part.
Fleshy – soft and juicy.
Indehiscent – fruits that do not have specialized structures for opening and releasing the seeds; they remain closed after the seeds ripen and are opened by animals, weathering, fire, or other external means.
Mesocarp – the middle layer of the pericarp.
Pericarp – the body of the fruit from its outside surface to the chamber where the seeds are, including the outside skin of the fruit and the inside lining of the seed chamber.
Suture – the seam along which the fruit opens; normally in most fruits it is where the carpel or carpels are fused together.
Cladautoicous – male and female inflorescences are on separate branches of the same plant.
Dioicous – having two forms of gametophyte, one form bearing antheridia and one form bearing archegonia.
Gonioautoicous – male is bud-like in the axil of a female branch.
Incubous – describing the arrangement of leaves of a liverwort; contrast with succubous.
Inflorescence – cluster of flower
Involucre – a tube of thallus tissue that protects the archegonia.
Monoicous – having a single form of gametophyte bearing both antheridia and archegonia, either together or on separate branches.
Paraphyses – sterile hairs surrounding the archegonia and antheridia.
Perianth – a protective tube that surrounds the archegonia, characterising the Jungermannialean liverworts.
Perichaetium – the cluster of leaves with the enclosed female sex organs.
Perigonium – the cluster of leaves with the enclosed male sex organs.
Pseudautoicous – dwarf male plants growing on living leaves of female plants.
Pseudoperianth – an involucre that resembles a perianth, but is made of thallus tissue, and usually forms after the sporophyte develops.
Rhizautoicous – male inflorescence attached to the female stem by rhizoids.
Succubous – describing the arrangement of leaves of a liverwort; contrast with incubous.
Synoicous – male and female sex organs are on the same gametophyte, but are not clustered.
Amphithecium – the external cell layers of the developing sporangium of a bryophyte. (Note: this term is also used in the mycology of lichens.)
Anisosporous – anisospore production is a rare condition in dioecious bryophytes; meiosis produces two small spores that develop into male gametophytes and two larger spores that develop into female gametophytes; contrast Isosporous.
Annulus – in mosses, cells with thick walls along the rim of the sporangium and where the peristome teeth are attached.
Allioideae is a subfamily of monocot flowering plants in the family Amaryllidaceae, order Asparagales. It was formerly treated as a separate family, Alliaceae. The subfamily name is derived from the generic name of the type genus, Allium. It is composed of about 18 genera.
Botany, also called plant science(s), plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek word βοτάνη (botanē) meaning "pasture", "grass", or "fodder"; βοτάνη is in turn derived from βόσκειν (boskein), "to feed" or "to graze". Traditionally, botany has also included the study of fungi and algae by mycologists and phycologists respectively, with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists (in the strict sense) study approximately 410,000 species of land plants of which some 391,000 species are vascular plants (including approximately 369,000 species of flowering plants), and approximately 20,000 are bryophytes.Botany originated in prehistory as herbalism with the efforts of early humans to identify – and later cultivate – edible, medicinal and poisonous plants, making it one of the oldest branches of science. Medieval physic gardens, often 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, and 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, growth and differentiation, reproduction, biochemistry and primary metabolism, chemical products, development, diseases, evolutionary relationships, systematics, 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, oil, rubber, fibre and drugs, in modern horticulture, agriculture and forestry, plant propagation, breeding and genetic modification, in the synthesis of chemicals and raw materials for construction and energy production, in environmental management, and the maintenance of biodiversity.
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 also List of Latin and Greek words commonly used in systematic names. You can help by adding illustrations that assist an understanding of the terms.
The following is a defined list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular or irregular, may be smooth or bearing hair, bristles or spines. For more terms describing other aspects of leaves besides their overall morphology see the leaf article.
Habit is equivalent to habitus in some applications in biology; the term refers variously to aspects of behaviour or structure, as follows:
In zoology (particularly in ethology), habit usually refers to aspects of more or less predictable behaviour, instinctive or otherwise, though it also has broader application. Habitus refers to the characteristic form or morphology of a species.
In botany habit is the characteristic form in which a given species of plant grows (see Glossary of plant morphology#Plant habit).
Hippeastrum () is a genus of about 90 species and over 600 hybrids and cultivars of perennial herbaceous bulbous plants. They generally have large fleshy bulbs and tall broad leaves, generally evergreen, and large red or purple flowers.
Hippeastrum is a genus in the family Amaryllidaceae (subfamily Amaryllidoideae, tribe Hippeastreae, and subtribe Hippeastrineae). The name Hippeastrum, given to it by William Herbert, means "Knight's Star", although precisely what Herbert meant by the name is not certain. For many years there was confusion among botanists over the generic names Amaryllis and Hippeastrum, one result of which is that the common name amaryllis is mainly used for cultivars of this genus, often sold as indoor flowering bulbs particularly at Christmas in the northern hemisphere. By contrast the generic name Amaryllis applies to bulbs from South Africa, usually grown outdoors. The genus is native to tropical and subtropical regions of the Americas from Argentina north to Mexico and the Caribbean.
Reproduction is generally by allogamy (cross-pollination) and Hippeastrum may be propagated by seed or offset bulbils (bulblets), although commercial ventures use in vitro techniques, or splitting of the bulb into sections. The genus has been intensely bred and cultivated since the early nineteenth century to produce large colourful showy flowers. In temperate climes these can be placed outside in the summer, and after a dormancy period, be induced to rebloom inside in the winter.
Nerine (nerines, Guernsey lily, Jersey lily, spider lily) is a genus of flowering plants belonging to the family Amaryllidaceae, subfamily Amaryllidoideae. They are bulbous perennials, some evergreen, associated with rocky and arid habitats. They bear spherical umbels of lily-like flowers in shades from white through pink to crimson. In the case of deciduous species, the flowers may appear on naked stems before the leaves develop. Native to South Africa, there are about 20–30 species in the genus. Though described as lilies, they are not significantly related to the true lilies (Liliaceae), but more closely resemble their relatives, Amaryllis and Lycoris. The genus was established by the Revd. William Herbert in 1820.
Nerines have been widely cultivated and much hybridized worldwide, especially Nerine bowdenii, N. sarniensis and N. undulata (previously known as N. flexuosa). The hybrid cultivar 'Zeal Giant' has gained the Royal Horticultural Society's Award of Garden Merit. The other 20 species are rarely cultivated and very little is known regarding their biology. Many species are threatened with extinction due to the loss or degradation of their habitat.
Plant life-form schemes constitute a way of classifying plants alternatively to the ordinary species-genus-family scientific classification. In colloquial speech, plants may be classified as trees, shrubs, herbs (forbs and graminoids), etc. The scientific use of life-form schemes emphasizes plant function in the ecosystem and that the same function or "adaptedness" to the environment may be achieved in a number of ways, i.e. plant species that are closely related phylogenetically may have widely different life-form, for example Adoxa and Sambucus are from the same family, but the former is a small herbaceous plant and the latter is a shrub or tree. Conversely, unrelated species may share a life-form through convergent evolution.
While taxonomic classification is concerned with the production of natural classifications (being natural understood either in philosophical basis for pre-evolutionary thinking, or phylogenetically as non-polyphyletic), plant life form classifications uses other criteria than naturalness, like morphology, physiology and ecology.
Life-form and growth-form are essentially synonymous concepts, despite attempts to restrict the meaning of growth-form to types differing in shoot architecture. Most life form schemes are concerned with vascular plants only. Plant construction types may be used in a broader sense to encompass planktophytes, benthophytes (mainly algae) and terrestrial plants.A popular life-form scheme is the Raunkiær system.
Symmetry in biology is the balanced distribution of duplicate body parts or shapes within the body of an organism. In nature and biology, symmetry is always approximate. For example, plant leaves – while considered symmetrical – rarely match up exactly when folded in half. Symmetry creates a class of patterns in nature, where the near-repetition of the pattern element is by reflection or rotation.
The body plans of most multicellular organisms exhibit some form of symmetry, whether radial, bilateral, or spherical. A small minority, notably among the sponges, exhibit no symmetry (i.e., are asymmetric). Symmetry was once important in animal taxonomy; the Radiata, animals with radial symmetry, formed one of the four branches of Georges Cuvier's classification of the animal kingdom.
A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very similar appearance), as in Magnolia, or because, although it is possible to distinguish an outer whorl of sepals from an inner whorl of petals, the sepals and petals have similar appearance to one another (as in Lilium). The term was first proposed by Augustin Pyramus de Candolle in 1827 and was constructed by analogy with the terms "petal" and "sepal". (De Candolle used the term perigonium or perigone for the tepals collectively; today this term is used as a synonym for "perianth".)
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