The botanical glossary used in Southwest Desert Flora is an alphabetical list of words or terms relevant to the descriptions here. In addition to the more difficult or unusual words defined here the glossary also provides definitions to some of the more common day-to-day botanical words that are not necessarily understood by all readers. This glossary is regularly updated or modified.
[A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Y] [Z]
Abaxial The side away from the axis, for instance the
lower surface of a flowering plant leaf; compare Adaxial).
Acaulescent An adjective descriptive of a plant that has no apparent stem, or at least none visible above ground. Examples include some species of Agave, Oxalis and Attalea.
Acerate Acerose; needle-shaped (long and pointed)
Achene A small dry indehiscent one seeded fruit.
Actinomorphic Regular; radially symmetrical; may be bisected into similar halves in at least two planes. Applies e.g. to steles and flowers in which the perianth segments within each whorl are alike in size and shape; compare
Regular; contrast with Asymmetrical, Irregular, Zygomorphic.
Aculeate Armed with prickles; e.g. the stem of a rose.
Acute Sharply pointed; converging edges making an angle of less than 90°; compare
Adaxial The side next to the axis; e.g. the
upper surface of a flowering plant leaf; compare Abaxial.
Adnate Grown or fused to an organ of a different kind, especially along a margin; e.g. a stamen fused to a petal; compare
Connate and Caudex.
Alkaline soil Alkaline or alkali, soils are clay soils with high pH (> 8.5), a poor soil structure and a low infiltration capacity. Often having a hard 'pan' or hard calcareous layers from 1½ feet or deeper.
Alternate Leaves or flowers borne singly at different levels along a stem includes spiralled parts; or (as preposition) when something occurs between something else, for example stamens alternating with petals; compare
Androecium Male parts of flower; the stamens of a flower collectively.
Androgynous With male and female flowers in the same inflorescence.
Angiosperms Flowering plants; plants with developing seeds enclosed in an ovary.
Annual A plant that completes its life cycle and dies within one year.
Anther Pollen-bearing part of the stamen.
Anthese 1. (of a flower) the period during which pollen is presented and/or the stigma is receptive.
2. (of a flowering plant) the period during which flowers in anthesis are present. note: not defined for some cases, such as when pollen is released in the bud.
Antrorse Directed towards or upwards, e.g. of hairs on a stem. See also Retrorse.
Pollen-bearing part of the stamen.
Apetalous Without petals.
Apex (plural apices) The tip; the point furthest from the point of attachment.
Appendage A secondary part attached to the main structure; an external growth that seldom has any obvious function.
Appressed Pressed closely, but not fused; e.g. leaves against a stem.
Arborescent Tree-like in growth or general appearance.
Areole (from areola) As with cacti, the area between the veinlets of a leaf or the region of a cactus bearing the flowers and/or spines.
Ascending Spreading horizontally, then becoming erect.
Asexual Of reproduction that does not involve the gametes; i.e. vegetative reproduction.
Irregular, unequal, lacking any plane of symmetry.
Auricle (adj. auriculate) usually of leaves; basal appendages shaped like an ear or earlobe.
Awn Fine bristle-like appendage; e.g. terminating or on the back of glumes and/or lemmas of some grass spikelet’s.
Axil The upper angle between one part of a plant and another; e.g. the stem and a leaf.
[B] ↵ Return to top
Basal At the base, situated or attached at the base.
Beak A prominent pointed terminal projection, especially of a carpel or fruit. adj. beaked.
Berry An indehiscent fruit, with the seeds immersed in the pulp, for instance tomato.
Biennial Plant which completes its life cycle and dies within the second year; usually also forms a basal rosette of leaves the first year and flowers and fruits the second year.
Bilabiate Having two lips; e.g. the form of the petals in many irregular flowers.
Bilateral Arranged on opposite sides; e.g. leaves on a stem.
Bipinnate Twice pinnate; for example of a compound leaf with individual leaflets pinnately divided.
Bipinnatisect A pinnatisect leaf with deeply dissected segments.
Bisexual Plant flowers bearing both male and female reproductive organs; usually, flowers with both stamens and carpels; hermaphrodite. See
Blade The lamina or flattened part of a leaf, excluding the stalk.
Bloom A fine white or bluish waxy powder occurring on plant parts, usually stems, leaves and fruits. It is easily removed by rubbing.
Bract Modified leaf associated with flower or inflorescence, differing in shape, size or color from other leaves (and without an axillary bud).
Bramble 1. A prickly shrub of the genus Rubus of the rose family, including the blackberry and the raspberry. 2. A prickly shrub or bush.
Bristle Straight stiff hair (smooth or with minute teeth).
Bulb (adj. bulbiferous), thick storage organ, usually underground, consisting of a stem and leaf bases (the inner ones fleshy).
Bur or Burr Loosely, a prickly fruit; a rough or prickly propagule consisting of a seed or fruit and associated floral parts or bracts.
[C] ↵ Return to top
Caducous Falling off early, for example the sepals of poppies, that fall off when the petals begin to open; compare
Persistent and Fugacious.
Caespitose A tufted form or growth; e.g. the growth form of some grasses, growing in tufts.
Calyx (Plural calyces) the outer whorl of a flower, usually green; the sepals of one flower collectively.
Calyx tube A tube formed by the fusion of the sepals (calyx), at least at the base.
Canescent Approaching white in color, covered with dense white (or grayish-white tricomes) down or wool.
Capitulum A dense cluster of sessile, or almost sessile, flowers or florets; a head.
Capsule A dry fruit formed from two of more united carpels and dehiscing when ripe (usually by splitting into pieces or opening at summit by teeth or pores).
Carpel The basic female reproductive organ in flowering plants.
Catkin A spike, usually pendulous, in which the mostly small flowers are unisexual and without a conspicuous perianth; e.g. willows, poplars, oaks and casuarinas. The individual flowers often have scaly bracts; they are generally wind-pollinated. The catkins are usually shed as a unit.
Caudex (plural: caudices) Literally the stem of a plant, but also used to mean a rootstock, or particularly a basal stem structure or storage organ from which new growth arises. See also
Caudiciform Literally meaning "stem-like" or "caudex-like", is sometimes used to mean "pachycaul", meaning "thick-stemmed". See also
Caulescent Having a leafy stem above ground, as contrasted with
Acaulescent and Scapose.
Cauline Borne on an aerial stem, e.g. leaves, flower or fruits (when applied to the latter two organs, usually referring to older stems; = cauliflorous).
Chasmogamous Of flowers that self-pollinate and never open fully, or self-pollinate before opening; see
Cilia (singular cilium, adjective ciliate) Generally, hairs more or less confined to the margins of an organ, like eye-lashes; in motile cells, minute, hair-like protrusions which aid motility.
Circumscissile Describing any seed-vessel that splits along a circumference, with the upper part coming off as a lid.
Clambering A plant growing more or less erect by leaning or twining on another structure for support, or by clinging with tendrils.
Clasping A leaf without a petiole and whose base partially or completely surrounds a stem.
Claw Narrow, stalk-like basal portion of petal, sepal of bract.
Cleft Deeply cut about halfway to the midrib, as in many leaves and petals.
Cleistogamous Of flowers that self-pollinate and never open fully, or self-pollinate before opening; see
Climber A plant growing more or less erect by leaning or twining on another structure for support, or by clinging with tendrils.
Columnar Shaped like a column.
An assemblage, in nature, of plants that characteristically occur together.
Compound Composed of several parts, for instance a leaf with leaflets, a gynoecium with several carpels, or an inflorescence made up of smaller inflorescences.
Cone A fruit, usually woody, ovoid to globular, including scales, bracts or bracteoles arranged around a central axis, e.g. in gymnosperms, especially conifers and Casuarina.
Connate Fused to another organ (or organs) of the same kind; e.g. petals in a floral tube; compare
Adnate and Caudex.
Cordate Heart-shaped, with the notch lowermost; of the base of a leaf, like the notched part of a heart.
Corm Fleshy, swollen stem base, usually underground, storing food reserves, with buds naked or covered by very thin scales; a type of rootstock. Adjectives derived from "corm" include "cormose" and "cormous";.
Corolla Collective term for the petals of a flower.
Corona (adjective: coronate) literally, crown
1. in flowering plants, ring of structures that may be united in a tube, arising from the corolla or perianth of a flower and standing between the perianth lobes and the stamens. The trumpet of a daffodil is a corona.
2. in grasses, a hardened ring of tissue surmounting the lemma in some species.
Corymb (Adjective corymbose) inflorescence with branches arising at different points but reaching about the same height, giving the flower cluster a flat-topped appearance.
Crenate Leaf or fruit with blunt, rounded teeth or scalloped margin.
Crenulate Minutely scalloped.
Crisped Finely curled. A term generally applied to the edges of leaves and petals.
Culm In grasses, sedges, rushes, and some other monocotyledons, an aerial stem bearing the inflorescence; strictly, from the base of the plant to the lowest involucral bract (or base of the inflorescence).
Cultivar The term cultivar is derived from cultivated variety and denotes an assemblage of cultivated plants clearly distinguished by one or more characters (morphological, physiological, cytological, chemical or other); when reproduced (sexually or asexually), the assemblage retains its distinguishing characters. A cultivar may arise in cultivation or be introduced from the wild. It is a variant of horticultural interest or value. Cultivar names are written with single quotation marks around them e.g. 'Blue Carpet', 'Alba'. All new names established after 1 January 1959, must be in common language (that is, not in Latin) but names established in Latin prior to this date are retained in Latin form.
Cuneate Wedge-shaped; with straight sides converging at base. See Leaf shape.
Cyathia Plural of cyathium
Cyathium An inflorescence of unisexual flowers surrounded by involucral bracts, esp. the flowers of Euphorbia.
Cyme (Adjective cymose) Inflorescence in which the main axis (central stem) and all lateral branches end in a flower, terminal flower develops first (each lateral may be repeatedly branched.
Cypsela A dry, indehiscent, one-seeded fruit formed from an inferior ovary.
[D] ↵ Return to top
Deciduous Falling seasonally, for instance bark, leaves, petals; compare
Decompound Divided to more than one level, as in bipinnate leaves for example, in which the leaflets of what otherwise would be a pinnate leaf, are themselves pinnately divided
Decumbent Plants or plant parts with branches growing horizontally but turned or curving up at the extremity.
Decurrent Extending downwards beyond the point of insertion e.g. when the base of a leaf or a fungal gill is prolonged downwards along the stem in a raised line or narrow wing.
Deflexed Bent downwards; compare inflexed.
Dehiscence (Dehiscent) Splitting at maturity along a built-in line of weakness.
Deltoid With the shape of the uppercase Greek letter Δ, i.e. like a more or less equilateral triangle. See Leaf shape.
Dentate Toothed, botanically used to describe leaf margins.
Dichotomous Forking into two equal branches. This may result from an equal division of the growing tip, or may be sympodial, in which the growing tip is aborted and replaced. Typically refers to mode of branch growth, as in Aloe dichotoma, but also to other organs, such as the thorns of various species of Carissa (which morphologically are branches) and thalli or hyphae of various algae and fungi.
Diffuse Spreading widely and loosely.
Dioecious Of plant, when male and female reproductive structures develop on different individuals; of inflorescence, male and female flowers in separate inflorescence’s; compare
Disk or Disc A plate or ring of structures derived from the receptacle, and occurring between whorls of floral parts: in daisies, the central part of capitulum, hence disk flowers or florets.
Discoid Resembling a disc or plate, having both thickness and parallel faces and with a rounded margin. Also used to describe the flower head of Compositae where there are no ray florets, but only disc florets.
Disjunct Occurring in widely separated geographic areas, distinctly separate; applies to a discontinuous range in which one or more populations are separated from other potentially interbreeding populations far enough as to preclude gene flow between them.
Dissected Deeply divided; cut into many segments.
Distal Remote from the point of origin or attachment; the free end; compare
Diurnal Of the day; occurring or opening in the daytime.
Divergent Spreading in different directions, generally upward.
Drupe A succulent fruit formed from one carpel; the single seed is enclosed by a stony layer of the fruit wall; kernel; e.g. peaches and olives.
[E] ↵ Return to top
Elliptical (elliptic) Shaped like a flattened circle, symmetrical about both the long and the short axis; about twice as long as broad, tapering equally both to the tip and the base; oval.
Endemic Having a natural distribution restricted to a particular geographic region; see
Entire 1. not divided. 2. (of a margin) having a smooth margin, not lobed or toothed (it may be wavy or scalloped).
Epipetalous Of stamens that are attached to the petal.
Erect Upright, more or less perpendicular to the ground or point of attachment.
Estivate A period of reduced metabolic rate (dormancy) for reptiles and small mammals to avoid long dry hot summers.
Exserted Projected beyond, e.g. the stamens beyond the corolla tube.
Extinction, local or extirpated Local extinction, or extirpation, is the condition of a species (or other taxon) that ceases to exist in the chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions.
[F] ↵ Return to top
Farinaceous Powderiness that is mealy
Farinose (adjective farinaceous) Floury, covered with meallike particles, as often seen in Chenopoidum (Amaranthaceae).
Fascicle (adjective fasciculate) In botany a cluster or bundle of leaves or flowers growing crowed together, e.g. a tuft of leaves all arising from the same node such as pine needles.
Filament 1. Stalk of a stamen. 2. Thread, one or a few cells thick.
Filiform Thread-like. Pertaining to leaf shapes.
Filiferous Bearing threads, as sometimes the leaf margin.
Fissure A split or crack, often referring to fissured bark; also, a line or opening of dehiscence.
Floccose With a soft and woolly covering of hairs.
Floret Literally a small flower, but usually refers to the individual true flowers clustered within an inflorescence, particularly in inflorescences of the daisy and grass families.
Follicle A dry fruit formed from one carpel, splitting along a single suture, to which the seeds are attached; compare;
Pod (of legume).
Funnelform With a form gradually widening from the base to apex; funnel-shaped; compare
Forb/herb Vascular plant without significant woody tissue above or at the ground. Forbs and herbs may be annual, biennial, or perennial but always lack significant thickening by secondary woody growth and have perennating buds borne at or below the ground surface.
Fruit Seed-bearing structure in angiosperms formed from the ovary, and sometimes associated floral parts, after flowering.
Fugacious Disappearing, falling off, or withering; compare
Persistent and Caducous.
Fusiform Rod-shaped and narrowing gradually from the middle towards each end; spindle-shaped.
[G] ↵ Return to top
Glabrous Without surface ornamentation such as hairs, scales or bristles.
Glabrescent, Glabrate Becoming glabrous, hairless, or smooth; glabrate. Becoming glabrous, almost glabrous.
Glaucous Botanical adjective, leaves or other herbage that is bluish-grey or green which describes the pale grey or bluish-green appearance of the surfaces of some plants.
Gland A secretory structure within or on the surface of a plant; (loosely) a smooth, usually shining, bead-like outgrowth.
Glandular hair Hairs tipped with a gland.
Globose, Globular Spherical. See also
Globulose Small or nearly spherical.
Glochid A barbed hair or bristle, e.g. the fine hairs in Opuntia.
Glutinous Sticky, gummy, gluelike. See also
[H] ↵ Return to top
Halophyte A plant adapted to living in highly saline habitats; a plant that accumulates high concentrations of salt in its tissues; compare
Hastate Leaf description, narrow and pointed but abruptly enlarged at the base into two acute diverging lobes; may refer only to the base of a leaf with such lobes; compare
Helicoid Coiled; of a cymose inflorescence, when the branching is repeatedly on the same side (the apex is often recurved); see
Herb A plant species lacking woody tissue when mature.
Herbaceaus Not woody; usually green, and soft in texture.
Hirsute Bearing coarse, rough, longish hairs. See
Hispid Having long erect rigid hairs or bristles, harsh to touch.
Holotype The single specimen designated as the type of a species by the original author at the time the species name and description was published. Also see
Hypanthium A tube or cup-like structure in a flower that includes the bases of sepals, petals, and stamens, and may or may not be connected (adnate) to the ovary.
[I] ↵ Return to top/p>
Imbricate Overlapping each other; of perianth parts, edges overlapping in the bud (the convoluted arrangement is a special form of imbrication.
Imparipinnate A pinnate leaf with an odd number of pinnae (terminated by a single leaflet); compare
Indehiscent Not opening in any definite manner at maturity; usually referring to fruit. Contrast with degiscent.
Indigenous Native to the area; its presence in that region is the result of only natural processes with no human intervention; not introduced and not necessarily confined to the region discussed (hardly distinct from ‘native’ but usually applied to a smaller area). The term is equivalent to "native" in less scientific usage. For example, the Joshua Tree (Yucca brevifolia) is native to parts of the southwest but indigenous to Joshua National Park, California. Compare;
Indumentum A collective term for a surface covering of any kind of
trichomes, e.g. hairs, scales.
Inflorescence Several flowers closely grouped together to form an efficient structured unit; the grouping or arrangement of flowers on a plant.
Involucre A structure surrounding or supporting, usually a head of flowers. In Asteraceae, it is the group of phyllaries (
bracts) surrounding the inflorescence before opening, then supporting the cup-like receptacle on which the head of flowers sits. In Euphorbiaceae it is the cuplike structure that holds the nectar glands, nectar, and head of flowers, and sits above the bract-like cyathophyll structure.
Involute Rolled inwards, for example when the margins of a leaf are rolled towards the
adaxial (usually upper) surface; compare Revolute.
Irregular Cannot be divided into two equal halves through any vertical plane. See also
Asymmetrical, compare Zygomorphic, Actinomorphic, Regular.
[J] ↵ Return to top
[K] ↵ Return to top
[L] ↵ Return to top
Lanceolate Lance-shaped, long, wider in the middle.
Laciniate Of lobes; with ends irregularly divided into deeply divided, narrow, pointed segments; Of margins; deeply divided into pointed segments in an irregular manner.
Leaflet The ultimate segments of a compound leaf.
Lectotype A specimen chosen by a later researcher to serve as if it were the holotype (specimen designated in the original description). It is chosen from among the specimens available to the original publishing author (the isotypes, syntypes and/or paratypes) of a scientific name when the holotype was either lost or destroyed, or when no holotype was designated. Also see
Legume 1. a fruit characteristic of the family Fabaceae, formed from one carpel and either dehiscent along both sides, or indehiscent.
2. a crop species in the family Fabaceae.
3. a plant belonging to the Fabaceae family).
Lepidote Covered with small scales.
Liana A woody climbing plant, rooted in the ground (liane is also used). Also see
Scandent and Vine.
Ligulate 1. Bearing a ligule.
Ligule 1. Small membranous appendage on the top of the sheath of grass leaves.
2. A minute adaxial appendage near the base of a leaf, e.g. in Selaginella.
3. Extended, strap-like corolla of some daisy florets. See Ligulate.
Ligulate 1. bearing a ligule.
Linear Very narrow in relation to its length, with the sides mostly parallel.
Lobe Part of a leaf (or other organ), often rounded, formed by incisions to about halfway to the midrib.
Lobulate With small lobes or shallowly lobed.
Lomentum A pod-like
indehiscent legume fruit that develops constrictions between the segments and at maturity breaks into one-seeded segments.
Lyrate Lyre-shaped; deeply lobed, with a large terminal lobe and smaller lateral ones.
[M] ↵ Return to top
Margin The edge, as in the edge of a leaf blade.
Mericarp One segment of a fruit (a schizocarp) that splits at maturity into units derived from the individual carpels, or a carpel, usually 1-seeded, released by the break-up at maturity of a fruit formed from 2 or more joined carpels. (see
Midrib The central, and usually most prominent, vein of a leaf or leaf-like organ; see
Monocarpic Flowering and setting seed only once before dying.
Monoecious Having the stamens and the pistils in separate flowers on the same plant; compare
Monotypic Containing only one taxon of the next lower rank, e.g. a family with only one genus, or a genus that includes only a single species.
[N] ↵ Return to top
Native Naturally occurring in an area, but not necessarily confined to it; see
Naturalized Describing a plant, introduced from another region, that grows and reproduces readily in competition with the natural flora.
Nectar A (usually sweet) fluid produced by the flowers of many plants, collected by bees and other insects.
Nectary (adjective nectariferous) a specialized gland that secretes nectar.
Nocturnal Botany: Opening at night; used of flowers.
Node The part of a stem where leaves or branches arise.
Nut A hard, dry, indehiscent fruit, containing only one seed.
Nutlet Nutlet (A small nut, one of the lobes or sections of the mature ovary of some members of the Boraginaceae, Verbenaceae, and Lamiaceae.
[O] ↵ Return to top
Obconic Of a fruit, hypanthium, pistil or calyx structure; an inverted cone shape, attached at apex.
Oblanceolate Leaf shape; top wider than bottom.
Oblong Length a few times greater than width, with sides almost parallel and ends rounded.
Obovate Of a leaf, a 2-dimensional shape of which the length is about 1.5 times the width, and widest above the center.
Obovoid Botany; Egg-shaped and solid, with the narrow end at the base: an obovoid fruit.
Obtuse Blunt or rounded at the tip or apex; converging edges making an angle of more than 90°; compare
Acute. See Leaf shape.
Ochrea (ocrea, ochrea) A sheath, formed from two stipules, encircling the node in Polygonaceae.
Opposite Leaves or flowers borne at the same level but on opposite sides of the axis; or (as verb) when something occurs on the same radius as something else, for example anthers opposite sepals; compare
Orbicular Flat and more or less circular.
Ovate Shaped like a section through the long-axis of an egg and attached by the wider end.
Ovoid Egg-shaped, with wider portion at base; 3-dimensional object, ovate in all sections through long-axis.
[P] ↵ Return to top
Palmate 1. leaf with veins radiating out from a central point (usually at the top of a petiole), resembling spread out fingers pointing away from the palm.
2. A compound palmate leaf has leaflets that radiate from a central point (usually at the top of a petiole).
Palmatifid Deeply divided into several lobes arising from more or less the same level.
Palmatisect Intermediate between palmate and palmatifid, i.e. the segments are not fully separated at the base; often more or less digitate.
Panicle (adjective paniculate) a compound raceme; an indeterminate inflorescence in which the flowers are borne on branches of the main axis or on further branches of these.
Papilla (plural papillae, adjective papillose, papillate) a small, elongated protuberance on the surface of an organ, usually an extension of one epidermal cell.
Pantropical In biogeography, a pantropical ("across the tropics") distribution is one which covers tropical regions of all continents. The genera Acacia is one example.
Pappus In daisy florets, a tuft or ring of hairs or scales borne above the ovary and outside the corolla (representing the missing calyx); a tuft of hairs on a fruit.
Paripinnate Having an even number of leaflets (or pinnae), that is terminated by a pair of pinnae as opposed to a single pinna; compare
Pedicel A pedicel is a stem that attaches single flowers to the inflorescence. It is the branches or stalks that hold each flower in an inflorescence that contains more than one flower. The stem or branch from the main stem of the inflorescence that holds a group of pedicels is called a peduncle.
Peduncle A stalk supporting an inflorescence, which is the part of the shoot of seed plants where flowers are formed.
Pellucid Transmitting light; for example, said of tiny gland dots in the leaves of e.g. Myrtaceae and Rutaceae that are visible when held in front of a light.
Pendulous Hanging loosely or freely, suspended so as to swing freely, to sway.
Pepo A type of berry formed from an inferior ovary and containing many seeds, usually large with a tough outer skin, for instance, pumpkin, cucumber.
Perennial A plant whose life span extends over several years.
Perfect A "perfect" flower has both
stamens and carpels, and may be described as bisexual; See Bisexual.
Perfoliate With its base wrapped around the stem (so that the stem appears to pass through it), e.g. of leaves and bracts.
Persistent Remaining attached to the plant beyond the usual time of falling, for instance sepals not falling after flowering, flower parts remaining through maturity of fruit; compare
Petal In a flower, one of the segments or divisions of the inner whorl of non-fertile parts surrounding the fertile organs, usually soft and conspicuously coloured; compare;
Petaloid Like a petal; soft in texture and coloured conspicuously.
Petiolate Subtended by a petiole.
Petiole The stalk of a leaf.
Petiolule The stalk of a leaflet.
Peduncle A stalk supporting an inflorescence, which is the part of the shoot of seed plants where flowers are formed.
Perfoliate With its base wrapped around the stem (so that the stem appears to pass through it), e.g. of leaves and bracts.
Perianth Parts of the flower; collective term for the petals (corolla) and sepals (calyx), particularly when both are very similar in appearance; compare
Phyllary (plural phyllaries) An individual bract within an
involucre or involucel.
Pilose Covered with soft, weak, thin and clearly separated hairs, which are usually defined as long and sometimes ascending.
Pinna (Plural pinnae) a primary segment of a compound leaf.
Pinnate A compound leaf with leaflets arranged on each side of a common petiole or axis; also applied to how the lateral veins are arranged in relation to the main vein. See pinnately.
Pinnately In a pinnate fashion (comparative more pinnately, superlative most pinnately)
Pinnately lobed A simple leaf with rounded or pointed lobes on each side of the
midrib or central and most prominent vein of a leaf or leaf-like organ.
Pinnatifid Having lobes with incisions that extend less than half-way toward the midrib. (Wiki usage notes, deeper incisions are pinnatipartite. Incisions reaching nearly to the midrib are pinnatisect.)
Pinnatipartite Having lobes with incisions that extend more than half-way, or up to the midrib.
Pinnatisect Having lobes with incisions reaching nearly to the midrib are pinnatisect. (Wiki usage notes, less deep incisions are pinnatifid.)
Pinnule Ultimate free division (or leaflet) of a compound leaf, or a pinnate subdivision of a multipinnate leaf.
Pistil 1. A single carpel when the carpels are free. 2. A group of carpels when the carpels are united by the fusion of their walls.
Pistillate (of a plant or flower) having pistils but no stamens.
Perennial A plant whose life span extends over several years.
Plumose Like a feather; with fine hairs branching from a main axis.
Pod 1. a legume, the fruit of a leguminous plant, a dry fruit of a single carpel, splitting along two sutures. 2. siliqua and silicula, the fruit of Brassicaceae, a dry fruit composed of two carpels separated by a partition.
Pome A fruit that has developed partly from the ovary wall but mostly from the hypanthium, e.g., apple.
Prickle (adjective: prickly) hard, pointed outgrowth from the surface of a plant (involving several layers of cells but not containing a vein); sharp outgrowth from the bark, detachable without tearing wood; cf.
Procumbent Spreading along the ground but not rooting at the nodes: not as close to ground as
Prostrate Lying flat on the ground. See
Proximal Near the point of origin or attachment. See
Pseudanthium A particular form of inflorescence occurring in the Asteraceae and Euphorbiaceae, in which multiple flowers are grouped together to form a flower-like structure, commonly called a head or capitulum.
Puberulous (puberulent) Covered with minute soft erect hairs.
Pubescent Downy; covered with short, soft, erect hairs.
[Q] ↵ Return to top
[R] ↵ Return to top
Raceme An unbranched flowering stem (inflorescence), continuously growing with flowers containing short stems (pediciles) along its axis.
Rachis (plural rachises; rachides) the axis of an inflorescence or a pinnate leaf; for example ferns; secondary rachis is the axis of a pinna in a bipinnate leaf distal to and including the lowermost pedicel attachment.
Radial With structures radiating from a central point as spokes on a wheel, for example, the lateral spines of a cactus.
Radical Springing from the root; clustered at base of stem.
Of daisies, of a capitulum, with ray florets surrounding disc florets.
Ray 1. Zygomorphic (ligulate) flowers in a radiate flowerhead, that is, ray-florets/flowers, for example Asteraceae.
2. Each of the branches of an umbel.
Receptacle The axis of a flower, in other words, floral axis; torus; for example in Asteraceae, the floral base or common receptacle is the expanded summit of the peduncle on which the flowers are inserted.
Retrorse (adverb retrorsely) Bent backwards or downwards. See also Antrorse.
Revolute Rolled under (downwards or backwards), for example when the edges of leaves are rolled under towards the midrib; compare Involute.
Rhizome A perennial underground stem usually growing horizontally. See also
Rhombic Like a rhombus: an oblique figure with four equal sides; compare trapeziform, trullate.
Rhomboid A four-sided figure with opposite sides parallel but with adjacent sides an unequal length (like an oblique rectangle); See also
Rose hip Rose hip, rose haw or rose hep, is the fruit of the rose plant, usually red-to-orange, but ranges from dark purple to black in some species.
Rosette A rosette is a circular arrangement of leaves, with all the leaves at a similar height. Though rosettes usually sit near the soil, their structure is an example of a modified stem.
Rotate Circular and flattened; for example a corolla with a very short tube and spreading lobes (for instance some Solanaceae))
Runcinate Sharply pinnatifid or cleft, the segments directed downward.
[S] ↵ Return to top
Sagittate Leaf description, shaped like the head of an arrow; narrow and pointed but gradually enlarged at base into two straight lobes directed downwards; may refer only to the base of a leaf with such lobe; compare Hastate.
Saline soil Soils containing high levels of salts from natural conditions, or from agricultural practices, so as to negatively impact successful plant growth.
Salverform Trumpet-shaped; with a long, slender tube and a flat, abruptly expanded limb; compare
Samara A dry, indehiscent fruit with its wall expanded into a wing, e.g. Maple trees (Acer).
Scabrid (scabrous) Rough to the touch with short hard emergences or hairs.
Scale 1. a reduced or rudimentary leaf, for example around a dormant bud.
2. a flattened epidermal outgrowth, such as those commonly found on the leaves and rhizomes of ferns.
Scandent Climbing, by whatever means. Also see
Vine and Liana.
Scape (adjective scapose) A stem-like flowering stalk of a plant with radical leaves.
Scapose Having the floral axis more or less erect with a few leaves or devoid of leaves; consisting of a scape.
Scarious Of plant parts or surfaces that may be stiff or scaly, dry membranous appearance, shriveled, they are often not green in color but yellowish, whitish or brownish.
Schizocarp A dry fruit formed from more than one carpel but breaking apart into individual carpels (
mericarp) when ripe.
Scorpioid (Botany) Resembling a scorpion's tail, as in a scorpioid cyme; circinate; of a cymose inflorescence, when it branches alternately on one side and then the other; compare
Serrate Toothed with asymmetrical teeth pointing forward; like the cutting edge of a saw.
Serrulate Finely serrate.
Semiterete (or semi-terete), rounded on one side, but flat on the other; compare
Sepal In a flower, one of the segments or divisions of the outer whorl of non-fertile parts surrounding the fertile organs, usually green; compare petal; compare
Sessile Without a stalk, e.g. of a stigma, when the style is absent or a leaf without a stalk.
Sheathing Leafy rolled or tubular structure on the lower part of a leaf; clasping or enveloping the stem, most often on sedges or grasses.
Shrub Perennial, multi-stemmed woody plant that is usually less than 4 to 5 meters (13 to 16 feet) in height. Shrubs typically have several stems arising from or near the ground, but may be taller than 5 meters or single-stemmed under certain environmental conditions. Applies to vascular plants only.
Silicle A fruit (seed capsule) of 2 fused carpels with the length less than three times the width. When the length is greater than three times the width of the dried fruit it is referred to as a silique; compare
Silique A fruit (seed capsule) of 2 fused carpels with the length being more than three times the width. When the length is less than three times the width of the dried fruit it is referred to as a silicle; compare
Simple Undivided, for instance a leaf not divided into leaflets (note, however, that a simple leaf may be entire, toothed or lobed) or an unbranched hair or inflorescence.
Sinuate With deep, wave-like depressions along the margins, but more or less flat; compare undulate. compare
Solitary Single, of flowers that grow one plant per year, one in each axil, or widely separated on the plant; not grouped in an inflorescence.
Spathe (adj. spathaceous), a large bract ensheathing an inflorescence. Traditionally any broad flat blade.
Spathulate (spatulate) Spoon-shaped; broad at the tip with a narrowed projection extending to the base.
Spike (adjective spicate) an unbranched, indeterminate inflorescence in which the flowers are without stalks; cf. raceme.
Spine (adjective spinose) a stiff, sharp structure, formed by the modification of a plant organ that contains vascular tissue; e.g. a lateral branch or a
stipule; includes thorns.
Spinescent Ending in a spine; modified to form a spine.
Spreading Extending horizontally, for example branches; standing out at right angles to axis, for example leaves or hairs.
Stalk The supporting structure of an organ, usually narrower in diameter than the organ.
Stamen (adjective staminate) Male organ of a flower, consisting (usually) of a stalk (
Filament) and a pollen-bearing portion ( Anther).
Staminate (of a plant or flower) having stamens but no pistils.
Stellate Star-shaped, for example a type of hair.
Stigma The pollen-receptive surface of a carpel or group of fused carpels, usually sticky; usually a point or small head at the summit of the style.
Stipitate Stalked; borne on a stipe; of an ovary, borne on a gynophore.
Stipulate Bearing stipules.
Stipule Small appendage at the bases of leaves in many dicotyledons.
Stolon Slender, prostrate or trailing stem, producing roots and sometimes erect shoots at its nodes. See also
Strigose Having stiff, straight, closely appressed hairs or bristles: strigose leaves.
Style An elongated part of a carpel, or group of fused carpels, between the ovary and the stigma.
Subglobose Inflated, but less than spherical. See also
Subshrub Low-growing shrub usually under 0.5 m (1.5 feet) tall, never exceeding 1 meter (3 feet) tall at maturity. Applies to vascular plants only. A dwarf-shrub in the FGDC classification.
Subtend To stand beneath or close to, as in a bract at the base of a flower.
Subulate Very narrow, linear, and tapering gradually from the base to a fine point, awl-shaped.
Suffrutescent Comparative more suffrutescent, superlative most suffrutescent. Slightly woody or shrubby at the base. Subshrub or undershrub.
Suffrutex A subshrub.
Sympetalous With united (
connate or fused) petals. Capable of being divided into at least two equal, mirror-image halves (e.g.
zygomorphic) or to have rotational symmetry (e.g. Regular, Actinomorphic). Contrast with Irregular, Asymmetrical.
[T] ↵ Return to top
Tendril A slender organ (modified e.g. from stem, leaf, leaflet or stipule) used by climbing plants to cling to an object.
Tepal Part of a flower or
perianth segment, either sepal or petal; usually used when the parts of the perianth are difficult to distinguish, e.g. the petals (caylx) and sepals (corolla) share the same color, or the petals are absent and the sepals are colorful.
Terete Circular in cross-section; more or less cylindrical without grooves or ridges; compare
Terminal Situated at the tip or apex.
Ternate In groups of three; of leaves, arranged in whorls of three; of a single leaf, with the leaflets arranged in groups of three.
Thorn A sharp, stiff point, usually a modified stem, that cannot be detached without tearing the subtending tissue; a spine; cf. prickle.
Tree Perennial, woody plant with a single stem (trunk), normally greater than 4 to 5 meters (13 to 16 feet) in height; under certain environmental conditions, some tree species may develop a multi-stemmed or short growth form (less than 4 meters or 13 feet in height). Applies to vascular plants only.
Trichomes In non-filamentous plants, any hair-like outgrowth from epidermis, e.g. a hair or bristle; sometimes restricted to unbranched epidermal outgrowths.
Trifoliolate or Trifoliate A compound leaf of three leaflets, for example a clover leaf.
Tomentose Leaf or other surfaces covered in dense, soft, often matted short hairs, sometimes woolly.
Tunicate Having successive, close-fitting concentric coats, as in an onion bulb.
[U] ↵ Return to top
Umbel (adjective umbellate) A racemose inflorescence in which all the individual flower stalks arise in a cluster at the top of the peduncle and are of about equal length; in a simple umbel, each stalk is unbranched and bears only one flower; a cymose umbel is an apparent umbel but its flowers open centrifugally.
Undulate Wavy and not flat; compare
Unispecific Of one species; monospecific; such as the former Cuscutaceae Family containing the single genus Cuscuta.
Unispexual Of one sex; bearing only male or only female reproductive organs, dioecious, dioicous. See Sexual reproduction in plants.
Utricle A small bladder; a membranous bladder-like sac enclosing an ovary or fruit; in sedges a fruit in which the pericarp is larger than, and loosely encloses, the seed.
[V] ↵ Return to top
Variegated Irregularly marked with blotches or patches of another color.
Venation The arrangement of veins in a leaf.
Villous Abounding in or covered with long, soft, straight hairs; shaggy with soft hairs.
Vine A plant that climbs by means of trailing, twining stem or runner. Also see
Scandent and Liana.
Viscid Sticky; coated with a thick, syrupy secretion.
[W] ↵ Return to top
Whorl A ring of organs borne at the same level on an axis, for example leaves, bracts or floral parts.
[X] ↵ Return to top
Xerophyte A plant generally living in a dry habitat, typically showing xeromorphic or succulent adaptation; a plant able to tolerate long periods of drought; compare
[Y] ↵ Return to top
[Z] ↵ Return to top
symmetrical; symmetrical about one vertical plane only; applies to flowers in which the perianth segments within each whorl vary in size and shape; compare Actinomorphic, Irregular.
Wikipedia contributors, 'Glossary of botanical terms', Wikipedia, The Free Encyclopedia, 20 April 2015, 19:23 UTC, http://en.wikipedia.org/w/index.php?title=Glossary_of_botanical_terms&oldid=657370054>
https://en.wikipedia.org/wiki/ - Definitions