Glossary of Plant Terms

 

A to D

A

abaxial: facing away from the axis or stem, such as the lower surface of a leaf. cf. adaxial.

accessory fruit: a false fruit, a fruit or group of fruit formed from one flower, in which the receptacle or hypanthium encloses the true fruit.

accrescent: expanding after flowering, usually refers to the sepals or calyx increasing in size and persisting around the mature fruit.

achene: a dry indehiscent 1-seeded fruit, from 1 carpel from a superior ovary, with the seed not fused to the fruit wall; e.g. in species of Clematis and Daphnandra. cf. cypsela.

acicular: needle-shaped.

actinomorphic: of a flower with the parts in each whorl, especially the sepals and petals and usually the stamens, not differing in shape, size or placement;  a regular flower. The flower therefore can be bisected symmetrically in several planes to produce similar halves. cf. zygomorphic.

acuminate: narrowed then tapering to a point, as for a leaf apex. cf. long-acuminateshort-acuminate, drip tip.

acute: evenly tapered to an angle of between 45 and 90 degrees, having a short sharp apex, as for a leaf apex. cf. obtuse.

adaxial: facing the axis or stem, such as the upper surface of a leaf. cf. abaxial.

adnate: attached to, fused to an organ of a different kind, e.g. stamens to a corolla tube. cf. connate.

adventitious: term describing any organ arising in an abnormal position, e.g. roots arising from the shoot system.

aerial: of an organ growing above ground level, as in adventitiousl roots, or aerial bulbils.

aggregate fruit: cluster of fruit derived from a single flower in which the carpels are free, or almost so, from each other and the fruit disseminated as a unit. e.g. as in species of Eupomatia and Rubus and in Hedycarya angustifolia. cf. multiple fruit.

alternate: of leaves inserted singly at different levels along the stem (commonly used to include spiral arrangement). cf. oppositesub-oppositewhorled and pseudo-whorled.

androecium: the male part of the flower, a collective name for the stamens of one flower. cf. gynoecium.

androgynophore: the column on which stamens and carpels are borne, sometimes the stamens or carpels may be rudimentary, as in Brachychiton bidwillii.

androphore: stamens united to form a column with the anthers at the apex, as in Hibiscus tiliaceus.

angiosperms: the flowering plants; plants with ovules enclosed in an ovary. cf. gymnosperms.

angled: of an organism, such a leaf lamina, with ± entire or straight sides except for 1 or more sharp angles.

annular: in a ring or arranged in a circle.

anther: the pollen-bearing organ of the stamen, the male reproductive organs of flowers.

anthesis: the time of flowering, the time when pollen is shed and the stigma is receptive.

anthocarp: an accessory fruit consisting of the true fruit surrounded by the base of the perianth or hypanthium, as in species of Pisonia.

antrorse: pointing or directed towards the apex, e.g. of hairs on a stem. cf. retrorse.

apex: the tip of an organ, e.g. of a leaf. pl. apices.

apical: at the top of an organ, e.g. of a stem or leaf or leaflet lamina.

apiculum: a small abrupt point, adj. apiculate

apocarp: a single fruitlet of a cluster of fruit or of multiple fruit, it may be indehiscent and fleshy and either berry-like or drupaceousindehiscent and dry or dehiscent and dry.

apocarpous: of a gynoecium with distinct and separated carpels in the flower, as in families Annonaceae, Ranunculaceae and Dilleniaceae. cf. syncarpous.

appendage: an attachment developed on and projecting from an organ, e.g. on anthers.

appressed: pressed closely against another organ, e.g. of hairs on a stem or leaf surface.

areolate: of surface pattern or venation, divided into many angular or squarish spaces, e.g. the venation and surface pattern in many species in the family Lauraceae, especially obvious in dried specimens, as in Endiandra discolor.

areole: (1) an area or space between veins or of a surface divided into a regular pattern, (2) the spine-bearing cushion of prickly pears, borne at a node, an extremely reduced axillary branch, as in Opuntia stricta.

aril: an expansion of the funicle of a seed growing partly or completely over the seed, usually fleshy and often brightly coloured, as in some species in family Sapindaceae. adj. arillate. cf. carunclestrophiole.

aristate: having a stiff bristle-like tip.

armed: with spines, thorns and/or prickles.

aromatic: scented, with a distinct smell when crushed, e.g. as in the leaves of many species of families Rutaceae and Myrtaceae.

articulated: jointed, as in the petiole of a one-foliolate leaf.

ascending: at first spreading horizontally and then becoming erect.

asymmetric: (oblique) of a leaf or leaflet base, the lamina or other organ having the sides unequal.

attenuate: tapered, narrowing gradually to an angle of less than 45 degrees, as for a leaf apex, or base.

auricles: ear-shaped lobes at the base of a leaf or other organ. adj. auriculate.

axil: the upper angle between one part of a plant and another part, e.g. the stem and a leaf, primary and secondary veins. adj. axillary.

axillary bud: the bud or buds formed in the angle between the stem and a leaf.

axis: the central stem of a plant or an inflorescence, or the elongated part of the receptacle on which floral organs are situated.

B

baccate: berry-like, with fruit having their seeds embedded in pulp. 

barbed: with bristles pointing backwards, each projection being a barb.

bark: the tissue outside the cambium on stems and branches of dicotyledonous angiosperms and most gymnosperms. Bark includes living and dead tissue, and is often quite thick.

barrel-shaped: shaped like a barrel, elongate and broadest at the centre, circular in T.S.

basifixed: attached at the base, e.g. of simple hairs. cf. medifixed

beak: a prominent terminal projection, e.g. of a fruit.

beaked: with a beak.

bearded: with a tuft of coarse hairs or hair-like appendages.

berry: a fleshy or pulpy indehiscent fruit with 1 or more seeds, the seeds embedded in the fleshy tissue; may be formed from either a superior or an inferior ovary.

berry-like: a fleshy or pulpy indehiscent fruit with 1 or more seeds  that looks like a berry. 

bifid: 2-fid; divided into 2 parts, for about half the length, as for a style or stigma.

bifoliolate: 2-foliolate; of a leaf, a compound leaf, with two leaflets.

bipinnate: 2-pinnate; of a compound leaf, with the lamina divided twice pinnately, i.e. with the pinnae themselves divided pinnately into pinnules.

bipinnatifid: 2-pinnatifid; of a simple leaf, with the primary lobes cut into smaller lobes (i.e. lobes pinnatifid). cf. bipinnate.

bisexual: of flowers, producing both viable stamens and ovaries.

biternate: 2-ternate; twice ternate, the 3 pinnae each divided into 3 pinnules (a total of 9 pinnules). cf. ternatetriternate.

blade: lamina; an expanded portion of a leaf or leaflet.

bloom: the white waxy covering on some fruit, leaves or stems, see pruinose and glaucous.

bole: the trunk of a tree below the lowest branch. cf. crown.

bootlace bark: refers to bark that is tough and fibrous and can be stripped away in long strips, as in species of Pimelea. The bark was used by early settlers as bootlaces and by aboriginals as string.

bract: a leaf-like structure, usually different in form and smaller than the foliage leaves and without an axillary bud, associated with an inflorescence or part of an inflorescence, as in Trochocarpa laurina and Eupomatia laurina.

bracteole: a secondary bract, a bract-like structure borne singly or in pairs on the pedicel or calyx of a flower, as in Trochocarpa laurina and Hernandia bivalvis.

branch: a lateral division of the growth axis.

branch stubs: small branchlets, often leafless and spinose, as in Glossocarya hemidema.

branchlet: a small branch.

bristle: a more or less straight stiff hair. adj. bristly.

broad-elliptic: broadest about the middle and with margins symmetrically curved and with a ratio of less than 2:1.

broad-ovate: oval in outline, broadest in the lowest third and with a ratio of less than 2:1.

brush: a term for rainforest, widely used in New South Wales, as in Jaspers Brush, Wingham Brush and Yarra Brush. cf. scrub.

bulb: a storage organ, usually underground, composed of stem and leaf bases.

bulbils: small bulbs; usually used to describe structures produced on above-ground parts of a plant, e.g. in the axil of leaves.

bullate: having a blistered or puckered surface; of a leaf surface conspicuously and regularly convex between the impressed veins (including the lateral and minor veins), and the surface appears blistered or quilted.

buttress: a flange protruding from the lower part of the trunk, frequent in rainforest trees, as in Elaeocarpus grandis and Ficus macrophylla.

C

caducous: falling or being shed early in the developmental stage of an organ or structure. cf. deciduous.

callosity: a thickened and hardened swelling, e.g. apex of teeth.

callus: a small hard protrusion or point.

calyptra: operculum; a cap-like structure covering the stamens and carpels in the flower bud. It is formed by the fusion of bracts, sepals and/or petals, staminodes. The calyptra, as in Eupomatia laurina, is usually shed as a complete unit just before the flower matures (at anthesis). adj. calyptrate.

calyx: collective term for the sepals of the flower, sometimes persistent in the fruit, as in Solanum ditrichum.

calyx tube: the tube formed by the fusion of sepals.

campanulate: bell-shaped, as of a corolla tube.

canopy: (1) often used as a collective term for the top layer (excluding emergents) in a forest; (2) the branches and foliage of a single tree.

capitate: head-like or in a head-like cluster.

capitulum: an inflorescence type, a dense cluster of more or less sessile flowers on an expanded receptacle, as in many species in family Asteraceae.

capsule: a dry dehiscent fruit formed from two or more fused carpels and dehiscing at maturity to release the seeds. adj. capsular.

capsule-like: in the form of a capsule, as in Pararistolochia where the fruit is capsular but it does not dehisce.

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 style between them. Carpels may be solitary or several and then free or fused together.

caruncle: a small aril-like structure on the testa (seed coat) near the micropyle. adj. carunculate. cf. arilstrophiole.

cataphyll: a scale leaf or leaf-like structure which do not develop into a true leaves; often develop in resting buds, and called cataphylls if they enlarge slightly as rudimentary leaves; axillary buds form in the axils of cataphylls.

caudate: with a narrow tail-like extension.

cauliflorous: with flowers or fruit produced on well-developed trunks or major branches, as in Ficus racemosa. cf. ramiflorous.

chaff: membranous scales, bracts or unfertilized ovules (as in many eucalypts).

channelled: with a groove running along its length, as along a petiole.

chartaceous: thin and stiff, papery. cf. membranous.

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

ciliate: having the margin fringed with hairs, resembling an eyelash.

circinate: coiled inwards upon itself, as in the developing fronds of ferns, e.g. Cyathea cooperi.

circular: shape of an an organ, as in circular scales with a stalk or point of attachment on its lower surface towards the centre, umbrella-like; peltate scales.

cladode: a photosynthetic stem whose foliage leaves are usually reduced or absent; green and stem-like, swollen and jointed (as in prickly pears), or expanded and leaf-like, as in species of Asparagus.

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

clavate: club-shaped, with a slender base and thickened apex.

closed forest: forest dominated by broad-leaved (or sometimes narrow-leaved) trees with dense crowns that form a ± continuous layer (canopy) and includes rainforest, mangrove forest and swamp sclerophyll forest. cf. open forest.

cobwebby: of an organ covered with long, loose entangled hairs, resembling an old cobweb.

coccus: see mericarp.

colleters: basal glands; a group or tuft of secretory hairs, sometimes looking like small warts when dried, often found near the base of the leaf lamina. In many species in family Apocynaceae, e.g. Marsdenia glandulifera.

coma: a tuft of hairs, especially on a seed, as in many seeds in the family Apocynaceae.

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.

compressed: flattened laterally. cf. depressed.

concolorous: with the same colour throughout or on both surfaces, as in leaves. cf. discolorousvariegated.

cone: dehiscent multiple fruit with the seeds enclosed by large leathery or woody bracts. When mature the bracts separate to release the seed. Used to describe the fruit of conifers and cycads and in Casuarina cristata.

conical: a 3-dimensional shape, cone-shaped, with the broad end at the base.

connate: joined together, united.

conspecific: belonging to the same species.

contorted: twisted; a form of development of buds in which each segment has one edge overlapping the next segment, as in Marsdenia liisae.

cool-temperate rainforest: CTRf, rainforest growing at higher altitudes with one to three species in the canopy layer.

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. Coppice shoots usually develop after damage to the trunk by fire, cutting, insect damage etc.

cordate: heart-shaped, often applied to the base of a leaf.

coriaceous: leathery, tough.

corolla: a collective term for the petals of a flower. 

corolla tube: the tube formed by the fusion of petals.

corolline corona: fleshy ridges or outgrowths of tissue attached to the corolla tube, usually in the sinuses of the lobes, as in many species in family Apocynaceae, e.g. Gymnanthera oblonga.

corona: a ring of tissue arising from the corollaperianth or staminal filaments of a flower and standing between the perianth lobes and stamens, as in Passiflora edulis where the corona is divided into several filaments.

corymb: an inflorescence (without a terminal flower) where the branches start at different levels, but end with all the flowers at the same height.

cosmopolitan: (of distribution) found in all parts of the world.

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

crenate: of a margin, with shallow, rounded teeth.

crenulate: finely crenate.

crested: with a terminal ridge or tuft.

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

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

cuneate: tapering gradually, wedge-shaped, e.g. of a leaf base, leaf apex, or lamina.

cupular: cup-shaped, as in the shape of an aril

cupule: a small cup-like organ, usually a structure which encloses the fruit, e.g. as in the fruit of Nothofagus moorei.

cusp: a sharp rigid point.

cylindrical: like a cylinder, long and narrow and circular in cross section.

cyme: determinate inflorescence in which each flower terminates each branch of the inflorescence and opens first, additional flowers are formed by the production of floral branches below the terminal flower. cf. monochasiumdichasium.

cymules: the ultimate portion of a cyme.

cypsela: a dry indehiscent 1-seeded fruit formed from 2 fused carpels and from an inferior ovary, a specialized term for the fruit in many species of the family Asteraceae, the cypsela is usually topped by a pappus.

cystolith: a mineral concretion, often calcium carbonate, produced in specific cells, such as the basal cells of specialized hairs, and appearing as warty-based hairs; often only the whitish hardened bases of the hairs remain on older stems and leaves and as a result the surface is scabrous, as in some species in the families Boraginaceae, Moraceae, Urticaceae and Acanthaceae.

D

dbh: an abbreviation for diameter at breast height, i.e. diameter of a tree trunk at 1.3 m above ground level.

deciduous: (1) falling seasonally, e.g. of the leaves and bark of some trees, (2) a plant losing its leaves for part of the year. cf. caducousevergreen.

decurrent: extending downwards beyond the point of insertion, e.g. of a petiole base extending down the stem as a ridge.

decussate: in pairs, with successive pairs borne at right angles to each other, e.g. of leaves.

dehiscence: the natural splitting of an organ at maturity, e.g. of an anther or dry fruit.

dehiscent: opening at maturity to release the contents, e.g of anthers and fruit. cf. indehiscent.

deltoid: a 3-dimensional shape, triangular.

dendritic: with a branched tree-like appearance, e.g of hairs.

depressed: flattened as if pressed down from the top; (1) of globose fruit, (2) of veins that appear lower than the leaf surface between them, as in bullate leaves.

depressed-globose: a solid shape, globose but pressed down from the top.

determinate: of growth or branching pattern, with a vegetative bud or flower bud terminating the main axis; of an inflorescence with the inflorescence or parts of the inflorescence ending in a flower or an aborted flower bud, as in a paniclethyrsoiddichasiummonochasium, etc. cf. indeterminate.

dichasium: cyme in which branches appear in regular opposite pairs. cf. monochasium.

dicotyledons: a major group of angiosperms (flowering plants) characterized by the embryo usually having 2 (rarely more) cotyledons (seed leaves). cf. monocotyledons.

didymous: in pairs, usually refers to anthers with 2 lobes and a very short connective between them.

didynamous: of stamens, in 2 pairs of unequal length, as in Gmelina leichhardti.

digitate: see palmate.

dimorphic: with two different forms, e.g. of leaves or of growth forms.

dioecious: with functional male and female flowers on different plants. cf. monoecious.

disc: a rim or dome of tissue between whorls of floral parts, formed from the receptacle, as in Drypetes deplancheiElaeodendron australe and Hedera helix; also as disk.

disc flower: a small, usually actinomorphic flower in the central part of the flower head in the family Asteraceae, sometimes called a disc floret.

discolorous: coloured differently on both surfaces, as in leaves. cf. concolorousvariegated.

disk: see disc (preferred spelling).

dissected: divided at least partially into segments.

distal: towards the free end or apex, away from the point of attachment.

distichous: 2-ranked; arranged in two rows on opposite sides of a stem and in the same plane.

divaricate: spreading widely e.g. of the branches on a plant, as in Eversitia vacciniifolia.

domatia: small structures on the lower surface of some leaves, usually consisting of depressions, partly enclosed by leaf tissue or hairs, usually located in the axils of the primary and secondary veins. sing. domatium.

dorsal: of a lateral organ, facing away from the subtending axis. cf. ventral.

dorsiventral: term describing leaves in which the upper and lower surfaces differ from each other in texture, presence of hairs, stomates etc. cf. isobilateral.

drip tip: the acuminate apex of a leaf that is drawn out to a point; a typical feature of many rainforest trees in wetter habitats. cf. long-acuminateshort-acuminate.

drupaceous: (drupe-like) term describing a fruit which is like a drupe a drupe.

drupe: an indehiscent succulent fruit derived from one or more carpels in which the pericarp consists of three layers.

drupelet: a small drupe, as in species of Rubus.

dry rainforest: DRf. Rainforest that grows where rainfall is low or effectively low due to topographic conditions.

dry sclerophyll forest: an open forest in which scleromorphic (hard-leaved) shrubs form a layer below the trees (usually species of eucalypts). cf. wet sclerophyll forest.

dyad: in twos, a pair, as in some inflorescence, e.g. the ultimate 2-flowered units of some mistletoe inflorescences.

Copyright. © 2014, All rights reserved.