Glossary of Botanical Terms:

C3 plants: plants that use the C3 pathway of carboxylation and do not have specialized Kranz anatomy, i.e. the majority of autotrophic plants. See also Kranz anatomy.

C4 plants: plants that use the C4 pathway of carboxylation and have specialized Kranz anatomy. See also Kranz anatomy.

caducous: falling early, e.g. of stipules. cf. deciduous.

caespitose: growing in tufts.

callosity: a thickened and hardened swelling on the surface of an organ.

callus: (1) a small hard protrusion, e.g. on the labellum of some Orchidaceae; (2) a hard point below the lemma, in spikelets of Poaceae; (3) a protective layer of tissue formed over an injury. pl. calli.

calyculus: the collective term for the involucral bracts (or phyllaries) surrounding a head in the Asteraceae.

calyptra (operculum): a cap-like covering or lid of some flowers or fruits that becomes detached at maturity by abscission; e.g. (1) the cap on the buds of eucalypts, (2) the lid of circumsciss capsules.

calyptra scar: scar left when the calyptra has fallen away, as in eucalypt fruits.

calyx: the sepals of one flower collectively. pl. calyces.

calyx tube: a tube formed by the fusion of the sepals, but sometimes wrongly used in the sense of hypanthium.

cambium: the meristem (growing region) in woody stems and fruits that forms the woody tissue.

campanulate: bell-shaped.

campylotropous: of an ovule, with the body bent or curved to one side so that the micropyle is near the funicle; the embryo sac is curved. Fig. 21 C. cf. anatropous, amphitropous, hemitropous, orthotropous.

canaliculate: with a longitudinal groove or channel.

canescent: whitish or pale grey, usually from a covering of short fine hairs.

canopy: (1) the branches and foliage of a tree; (2) often used as a collective term for the crowns of trees in a forest.

capillary: slender, hair-like.

capitate: (1) shaped like a head; (2) in a head-like cluster.

capitulum (head): a dense cluster of more or less sessile flowers, e.g. in Asteraceae a group of florets sessile on a common receptacle. Fig. 17 O & P.

capsule: a dry dehiscent fruit derived from two or more carpels. Capsules may dehisce in various ways. Fig. 18 L–P. adj. capsular.

carina: a keel. adj. carinate.

carnivorous: capable of trapping and digesting animals.

carpel: a unit of the female part of the flower (gynoecium), consisting of an ovary bearing one or more ovules, a receptive stigma, and often a stalk-like style between them. A flower can have a solitary carpel (and then the terms gynoecium and pistil are synonymous, Fig. 13 A & G) or more than one carpel. If the carpels (pistils) are free the gynoecium is apocarpous or if the carpels are fused the gynoecium (pistil) is syncarpous (or compound).

carpodium: a sterile female flower in which the ovary and ovule is reduced into a club-shaped structure with a short style but lacks the expanded stigma, as in Typha.

carpophore: in a fruit, the stalk of a mericarp. Fig. 18 H.

cartilaginous: hard and tough; gristly.

caruncle (strophile): an appendage of a seed, near the hilum (scar). Fig. 19 D. adj. carunculate.

caryopsis: a dry, indehiscent 1-seeded fruit in which the seed is fused to the wall of the fruit, as in family Poaceae. Fig. 18 S.

cataphyll: (1) a scale leaf associated with a vegetative part of a plant; (2) a leaf composed mostly of a leaf sheath or base with the lamina reduced to a minute awn, e.g. in some Juncus species.

catkin: a dense spike-like inflorescence, usually pendulous, with minute unisexual flowers.

caudate: bearing a narrow tail-like appendage.

caudex: a thick, erect trunk above and/or below ground level, e.g. in cycads.

caudicle: the stalk for a pollinium derived from the anther (as in some orchids); an elastic extension of some pollinia.

caulescent: with a trunk.

cauliflory: the production of flowers or fruits on well-developed trunks or major branches. adj. cauliflorous. cf. ramiflory.

cauline: borne on the more or less elongated aerial portion of a stem, e.g. describing leaves. cf. radical.

cell: the basic unit of plant structure consisting, at least when young, of a protoplast surrounded by a wall.

centrifixed: of a two-branched organ attached by its centre, e.g. a hair.

centrifugal: directed, or developing, from the centre or axis outwards. cf. centripetal.

centripetal: directed, or developing, from the outside towards the centre or axis. cf. centrifugal.

chaff: (1) membranous scales or bracts; (2) thin dry unfertilized ovules among the fully developed seeds of a fruit, as in many eucalypts.

chalaza: the part of an ovule to which the end of the stalk (funicle) is attached. Fig. 21. adj. chalazal.

channelled: with edges curved round (like a gutter).

character: any feature of an organism or taxonomic group that can be measured, counted or otherwise assessed.

chartaceous: papery, opaque and thin.

chasmogamous: of flowers that are pollinated while open. cf. cleistogamous.

chlorophyll: pigment(s) constituting the green colouring matter in plants and absorbing radiant energy in photosynthesis.

chromosome: a thread-like structure in the nucleus of a cell, containing a linear sequence of genes.

cilia: hairs more or less confined to the margins of an organ. sing. cilium. adj. ciliate.

ciliate: having the margin fringed with hairs, resembling an eyelash. Fig. 14 I. cf. fimbriate.

ciliolate: having the margin minutely fringed.

cincinnus: a tight, modified helicoid cyme with short pedicels on the developed side.

circinate (circinnate): spirally coiled with the tip innermost as in the young fronds of many ferns. Fig. 11 A.

circular (orbiculate): a 2-dimensional shape with length and breadth more or less equal. Fig. 5 E.

circumsciss (circumscissile): breaking open along a transverse line so that the top (calyptra) comes off like a lid, as in some capsules. Fig. 18 O.

cladode: a photosynthetic stem whose foliage leaves are usually reduced or absent.

clasping: surrounding or embracing, e.g. stem-clasping, of a lamina surrounding the stem.

class: a major taxonomic rank, between order and division.

classification: the establishing and defining of systematic groups; the assignment of organisms (plants) to groups within a system or hierarchy or ranks or categories. cf. systematics, taxonomy.

clathrate: latticed.

clavate: club-shaped.

claw: a narrow, stalk-like basal portion of a petal, sepal or bract. cf. limb.

cleistogamous: of flowers that remain closed and are self-pollinating and set fertile seed. cf. chasmogamous.

cleistogene: specialized florets produced at the base of some grasses in the leaf sheaths. These modified florets produce fertile diaspores without opening and they are different in appearance and structure from those in the inflorescence.

cline: continuous morphological variation in form within a species, or sometimes, between two species. adj. clinal.

clone: genetically identical organisms produced from a single parent by vegetative reproduction , or by development of ovules without fertilization.

closed forest (rainforest): a forest dominated by broad-leaved trees with dense crowns that form a continuous layer (canopy) and with one or more of the following growth forms.

club: of orchids (family Orchidaceae) when perianth segment swollen apically and that portion often covered in glands or glandular hairs.

cluster bract: a bract subtending a cluster of flowers.

coalesced: with like or unlike parts or organs partially fused in a more or less irregular fashion. cf. adhesion, adnate, cohesion, connate.

cobwebbed: covered with long weak, loosely entangled hairs, resembling a spiderweb; usually whitish. adj. cobwebby.

coccus: one of the segments (usually 1-seeded) of a distinctly lobed fruit which becomes separated at maturity; sometimes called a mericarp. Fig. 18 H & P. pl. cocci.

cohesion: the sticking together of two or more similar parts that are not organically fused. adj. coherent. cf. adhesion.

collateral: situated side by side; adjacent and on the same radius of an axis.

colliculate: of a surface, rough with low rounded protuberances. Fig. 16 A.

columella: the persistent central axis in some fruits and cones.

column: (1) (gynostemium) a structure formed by the union of stamens, style and stigmas, as in Orchidaceae, Asclepiadaceae and Stylidiaceae; (2) the lower part of an awn in grasses, when different in form from the upper part.

coma: a tuft of hairs, especially on a seed or fruit.

community: an assemblage of plants that naturally occur together.

complicate: folded together.

compound: composed of several more or less similar parts, as opposed to simple; e.g. of an ovary formed from several united carpels or of a leaf divided into leaflets. Fig. 3 A–F, I–M.

compressed: flattened in one plane, either dorsally (bringing the front and back closer together) or laterally (bringing the sides closer together).

concavo-convex: concave on one side and convex on the other.

concolorous: with the same colour throughout or on both surfaces. cf. discolorous.

conduplicate: folded flat together lengthwise, e.g. as in aestivation. Fig. 11 C.

cone: (1) a group of sporophylls arranged tightly on a central axis, as in cycads and conifers

conflorescence: a branch system bearing flowers in which the main axis bears uniflorescences, but is itself qualitatively different in structure from the uniflorescences.

confluent: merging or blending together.

conical: cone-shaped, with the broad end at the base.

connate: fusion of similar parts, e.g. petals into a corolla tube. cf. adnate.

connivent: coming into contact or converging.

connective: the sterile part of an anther connecting the loculi.

conspecific: belonging to one and the same species.

contiguous: touching but not fused, adherent, or coherent.

contorted: twisted; a form of imbricate aestivation in which each segment has one edge overlapping the next segment. Fig. 11 E.

contraligule: a tongue-shaped structure produced at the apex of the leaf sheath opposite the blade in Scleria.

convolute: rolled with margins overlapping. Fig. 11 D.

coppice shoot: a shoot developed from a dormant bud in the trunk or larger branches of a tree, the leaves on such a shoot often differ from the adult leaves and are called juvenile leaves (similar to sapling leaves); a common feature of many eucalypts and rainforest trees. Coppiceshoots usually develop after damage to the trunk by fire, cutting etc. Fig. 1 G.

cordate: of a leaf or leaf base, heart-shaped with a basal notch. Fig. 7 F.

coriaceous: leathery.

corm: a short, broad, fleshy, subterranean stem which produces aerial stems, leaves and flowers and in which food reserves are stored.

corolla: the petals of a flower collectively, frequently brightly coloured or white.

corona: any ring of tissue or appendage that stands between the perianth and the stamens, or on the perianth. e.g. as in Passiflora species.

cortex: the region of a stem or root surrounding the vascular cylinder but inside the epidermis.

corymb: an inflorescence (without a terminal flower) in which all the flowers are at the same level even though the pedicels arise at different levels. Fig. 17 K.

costa: a rib. adj. costate.

cotyledon: the first leaf or leaves of the embryo, present in the seed.

coumarin: a carbohydrate with a strong smell, as in some seeds and leaves.

crenate: of a margin, with shallow, rounded teeth. Fig. 8 B.

crenulate: finely crenate.

crested: with a terminal ridge or tuft.

crisped: very strongly, and usually finely, wavy. Fig. 8 I. cf. undulate.

crown: the part of a tree or shrub above the level of the lowest branch.

crustaceous: hard, thin and brittle.

cryptogam: a plant whose sexual reproductive parts are not conspicuous; a plant that produces spores, not seeds, in its sexual reproductive cycle, e.g. ferns, mosses, algae. cf. phanerogam.

cuboid: cube-like; a 3-dimensional shape.

cucullate: hooded.

culm: an aerial stem bearing the inflorescence, in grasses, rushes etc.

cultivar: cultivated variety, a variety developed in cultivation. An assemblage of cultivated individuals distinguished by any characters significant for the purposes of agriculture, forestry or horticulture, and which, when reproduced retains its distinguishing features.

cuneate: wedge-shaped, e.g. of a leaf or leaf base. Fig. 7 B.

cupule: a small cup. adj. cupular.

cupuliform: cup-shaped.

cusp: sharp, rigid point.

cuspidate: tapering into a sharp rigid point.

cyathium: an inflorescence of reduced unisexual flowers surrounded by involucral bracts, e.g. in Euphorbia species. Fig. 17 R.

cylindric: tubular or rod-shaped.

cyme: an inflorescence in which the main axis ends in a flower and further growth of the inflorescence is by one or more branches which themselves end in a flower (the main and lateral branches may bear bracteoles but have no bracts, leaves or nodes). adj. cymose. e.g. dichasium, monochasium. Fig. 17 D & E.

cymule: a small dichasium.

cypsela (an achene): the fruit formed in most Asteraceae; a dry indehiscent 1-seeded fruit formed from inferior ovary of 1 carpel, with the seed not fused to the fruit wall and usually topped by the pappus. Fig. 18 R.

cystoliths: mineral concretions, usually of calcium carbonate on a cellulose stalk, chiefly occurring in specialized hairs in some Urticaceae and Cannabaceae and in Acanthaceae; often appearing as tubercle-based hairs. Fig. 15 B.

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