Glossary

Glossary of Botanical Terms

abaxial: the side or surface facing away from the stem or axis

achene: a small, dry, one-seeded fruit of a typical Asteraceae flower, developed from an superior ovary and resembling a cypsela but without a surrounded calyx sheath

acicular: needle-shaped

acinaciform: scimitar-shaped

actinomorphic: radially symmetrical, as opposed to zygomorphic or bilaterally symmetrical, pertaining to circular floral shapes

adaxial: the side or surface facing the stem or axis

adnate: fused to an organ of a different kind

adventitious: applied to roots or other plant organs, arising from any point or organ other than the usual system, such as the root system of the plant appearing from above-ground stem nodes; also relate to buds and shoots

anemophilous: wind pollinated as opposed to entomophilous or insect pollinated

angiosperm: seed-bearing plant developing its seeds in an ovary (compare gymnosperm)

anisophyllous: bearing leaves in pairs of two or more shapes and sizes

annulus: a ring-like structure

anthesis: the opening or fully open and functional period of a flower

apical: pertaining to the apex or top

appressed: pressed close to or lying flat against

aril: fleshy seed appendage arising from the seed funicle or stalk

ascending: angled up and outwards from the point of attachment, pertaining to leaves or other plant parts

attenuating: tapering to a gradual, extended tip

awn: a stiff bristle as found on a grass fruit

axil: the angle between a leaf and the stem or surface from which it arises

barbate: bearded

berry: fleshy fruit covered by a soft pericarp; multiple seeds embedded in a pulp

bifid: cleft halfway into two parts

biramous: divided into two branches

bisexual: stamens and pistil both present in the same flower

bract: small leaf-like structure borne below a flower or group of flowers

bracteole: small, secondary bract

bristle: a coarse, erect hair, a stiff trichome

bryology: the science of mosses, liverworts and hornworts

calcareous: chalky, limestone-like, containing or looking like calcium carbonate

calyx: the outer covering of a flower, consisting of free or joined sepals

capsule: dry fruit comprising two or more carpels or cavities that dehisce to release seeds

carnose: fleshy

carpel: a single unit or segment of the female reproductive organ of a flower, consisting of an ovary holding ovules, a stigma and usually a style

carunculate: a warty, fleshy, naked outgrowth on a plant on a seed

cataphyll: a reduced scale leaf, bract or bracteole differing from a plant’s true leaves, adapted for other functions than photosynthesis

catkin: a dense, single sex, spike-like flowerhead lacking petals

caudex: underground, persistent stem, usually woody, often thick

caulescent: bearing a leafy stem aboveground

cladode: a flattened stem resembling a leaf

cladophyll: a photosynthetic branch or portion of a stem that resembles and functions as a leaf, a cladode

compound: consisting of several individual units

coppice: to resprout from near the base

corm: underground storage organ formed by a stem, often covered by dry leaf bases; a tuberous rootstock

corolla: the inner flower covering or envelope part of a flower consisting of petals, joined or free, often the most colourful floral part

corymb: a flat-topped raceme in which the individual flower stalks grow obliquely outwards to roughly the same height, the outermost flowers on longer stalks arising at lower levels

cotyledon: the primary leaf of an embryo

culm: the hollow stem of a grass or solid stem of a sedge, mostly solid in restios

cyme: a usually flat-topped or convex flower cluster in which the main axis and each branch end in a flower that opens before the flowers below or to the side of it; an inflorescence in which each floral axis terminates in a single flower

cypsela: a dry one-seeded fruit of a typical Asteraceae flower, developed from an inferior ovary and resembling an achene but surrounded by a calyx sheath

deciduous: leaves falling at the end of each growing season

decumbent: lying flat with the tip curved up

decussate: growing in opposite pairs, such as leaves, succeeding each other at right angles, resulting in four vertical arrays

dehiscent: opening spontaneously when ripe, pertaining to capsules or anthers

deltoid: shaped like an equal-sided triangle

dichasium: a simple cyme; a flowerhead comprising three flowers, the terminal one opening first

dichotomous: forking into equal branches

digitate: divided to a central point, like fingers

dioecious: bearing unisexual flowers, male and female ones on different plants

disc: 1. enlarged receptacle forming part of the calyx or corolla, usually a cushion, ring or cup, sometimes lobed or divided into nectary glands; 2. disc of florets in Asteraceae flowerhead centre

distichous: arranged in two vertical ranks or arrays on opposite sides of a stem; compare decussate

domatia: small depressions or swellings on lower leaf surfaces in the axils between leaf midribs and the main lateral veins comprising hair tufts or small pits

dorsal: the side facing away from the axis, at the back or below

drupe: a fleshy, usually one-seeded fruit that does not dehisce

echinate: bristly or prickly

ecotone: a transitional area of vegetation between two plant communities, such as where a forest and a grassland meet and integrate

elaiosome: fleshy structure attached to the seed of some plants, often rich in oil, attracting animals, particularly ants that disperse the seeds used as food

embryo: the rudimentary plant still enclosed in the seed

ensiform: sword-shaped

entomophilous: insect pollinated; compare anemophilous

ephemeral: short-lived

epicalyx: a ring of small bracts below the main calyx of a flower

epigeal: growing close above the ground, compare hypogeal

epiphyte: a plant growing on another plant without being parasitic

ericoid: leaves similar to Erica plants, narrow and with margins rolled under

exserted: protruding beyond

evanescent: disappearing quickly

falcate: curved like a scythe or sickle; crescent-shaped

family: a group of one or more genera believed to be related phylogenetically, usually separate from other groups

fascicle: a cluster of leaves or flowers emerging at about the same point

floret: small flower, usually of a many-flowered flowerhead or inflorescence

flowerhead: head-like inflorescence consisting of several florets usually densely together, a capitulum

follicle: a fruit formed from a single carpel, usually opening along a suture where the seeds are attached

forb: a non-woody plant other than a herb, grass, sedge or rush

friable soil: malleable, easily crumbled or pulverized soil that easily clumps in the hand unlike overly sandy soil

frond: leaf of a fern, palm or cycad

fruit capsule: a simple, dry, many-seeded, dehiscent fruit developing from a multi-carpellary, syncarpous ovary

frutescent: becoming shrubby or woody

funicle: a stalk connecting an ovule or a seed with the placenta

furcate: forked

geophyte: a herb growing renewed, often annually, from underground buds situated on a perennial organ such as a rhizome, corm or bulb

glabrous: lacking hairs or trichomes

glabrescent: becoming hairless

glaucous: blue-grey or blue-green; covered in a waxy or powdery bloom

glume: dry bract of flower spike in grasses, restios and sedges

guttation: the exudation of drops of xylem sap on the tips or edges of leaves of some vascular plants, such as grasses

gymnosperm: seed plant bearing ovules on the surface of a sporophyll; a plant bearing naked seeds; compare angiosperm

gynoecium: the innermost whorl of a flower comprising female floral parts

gynophore: the stalk bearing the female floral parts

halophyte: a plant that tolerates high levels of salt in its soil or water

haustorium: a specialized absorbing structure of a parasitic plant, such as the root-like outgrowth of dodder that penetrates host plant tissue and obtains nutrients from it

hemiparasite: a plant, such as mistletoe, that obtains some nourishment from its host but also photosynthesizes; also called a semiparasite

hirsute: coarsely hairy

hyaline: having a glassy, transparent appearance

hygrochastic: opening when wet, referring to fruit capsules like those of mesembs

hypanthium: a floral structure consisting of the bases of the sepals, petals, and stamens fused together

hypocotyl: the part of a germinating seedling or embryo below the cotyledon node that develops into the stem

hypogeal: growing below-ground, compare epigeal

hysteranthous: leaves emerging after the flowers have opened; compare synanthous

imbricate: overlapping like tiles on a roof

imparipinnate: of compound leaves also bearing a terminal leaflet or pinna, thus having an odd number of pinnae

incubous: a leaf arrangement in which the upper margin of each leaf lies above the lower margin of the next one; the opposite: succubous

indumentum: an outer covering, such as hairs or down on a plant or leaf

inflorescence: a group of flowers or the arrangement of flowers borne on a single stalk or peduncle

involucre: the modified leaves below and enveloping a flowerhead

keel: a longitudinal ridge, resembling a boat keel

legume: a member of the pea or Fabaceae family

liane: a woody climber growing rope-like stems

lignotuber: a woody swelling at a plant base or at the top of the root system where new shoots develop from adventitious buds, for instance after fire

ligule: a scale-like or thin, membranous projection on a grass stem or sheath, where it joins the grass blade, often hairy

limb: the outer, often expanded part of a corolla or calyx above the tube, throat or claw

limestone: pale, chalky rock

locule: a small cavity, chamber or compartment within an organ or plant part

marcescent: withering without falling off

mericarp: one of the separate parts or segments of a fruit that breaks off at maturity, associated with a single carpel

mesic: less extreme; in ecology, a mesic habitat is a type of habitat with a moderate or well-balanced supply of moisture, e.g., a mesic forest, a temperate hardwood forest, or dry-mesic prairie

midrib: the main nerve or vein of a leaf, usually central

monocarpic: flowering only once and then dying

monoecious: bearing unisexual flowers, both male and female ones on the same plant; compare dioecious

monophyletic: originating from a common ancestor

monotypic: a genus consisting of only one species or a family consisting of only one genus

mucro: an abrupt, projecting point as at the end of a leaf, continuing the midrib

nectar guide: floral cue for orientating pollinators to a nectar source

nectary: a nectar-secreting organ, usually in a flower, also on a leaf or stem

node: spaced points on a stem where leaves, branches or flowers originate

nut: a one-seeded indehiscent fruit including a hard, covering pericarp or shell

osmosis: the process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one

obovate: egg-shaped with broader end above the middle

ovate: egg-shaped with broader end below the middle

ovoid: three-dimensional shape of ovate outline

palmate: lobed or incompletely divided to a central point, compare digitate

panduriform: fiddle-shaped, pertaining to leaves having rounded ends and a contracted centre

papilla (plural papillae): a soft, nipple-shaped protuberance; a type of trichome

papillose: covered in minute, nipple-shaped protuberances

pappus: the ring or tuft of hairs, bristles or scales around the top of certain fruit

parietal: pertaining to the wall or outer surface of a body part

paripinnate: of compound leaves bearing no terminal leaflet, thus having an even number of leaflets

pedicel: a stalk of an individual flower

peduncle: a stalk of a group or cluster of flowers

pellucid: translucent

perennial: herb that remains alive for several years

perianth: the outer or covering floral parts, comprising calyx, corolla or both

pericarp: the part of a fruit formed by the wall of the ripened ovary

petal: a component or segment of the corolla of a flower, in some cases called a tepal

petiole: a leaf stalk

pilose: covered in long, straight, soft, spreading or erect hairs

pinnate: leaflets of a compound leaf arranged feather-like on opposite sides of a rachis

pistil: the female part of a flower comprising an ovary, a style and a stigma, the gynoecium

planoconvex: flat on one side and rounded on the other

plumose: feathery

pod: a seed vessel, often elongated, associated with legumes

pollen: the powdery cells found in an anther, containing the male reproductive nucleus

porrect: forwardly extended, perpendicular to the surface

procumbent: trailing along the ground without rooting at the nodes, pertaining to stems

protandrous: the male (anther) part of a flower ripening first

protogynous: the female parts (ovary and stigma) of a flower ripening first

pubescent: bearing soft, short hairs or trichomes of any type

pustule: a blister-like or pimple-like bulge or swelling

raceme: a flowerhead on which the main tip keeps producing younger flowers, the side-branches each producing single, stalked flowers

radical leaves: leaves that grow from the stem base, appearing to arise directly from the root

ray floret: ribbon-like floret around the margin of a daisy flower

receptacle: the upper, expanded tip of a flower stalk upon which the floral organs are borne

recurved: rolled or curved backwards or downwards

refugium: a location of an isolated or relict population of a once more widespread species

reniform: kidney-shaped

resupinate: facing downwards as orchid flowers after twisting around in the early bud phase

retuse: notched

rhipidium: a fan-shaped cyme, an inflorescence in which successive flower pedicels follow a zigzag path in the same plane, alternating on opposite sides of the peduncle

rhizome: horizontal, creeping underground rootstock or on the ground stem with buds, leaves or scales that differentiate it from a root

rhombic: diamond-shaped

rootstock: the rooted part of a plant

rostellum: a small, beak-like outgrowth compared to a diminutive rostrum; an extension of the stigma of an orchid flower

rosulate: leaves in a rosette or circle

rugose: having a rough, wrinkled or corrugated surface

saccate: pouched

scabrid: roughly short-haired

scale: a reduced leaf, usually sessile and not green

scandent: climbing like a vine or ivy

scape: a flower stalk rising directly from the root or rhizome; a naked peduncle rising direct from the plant base, often with radical or rosulate leaves below

secund: arranged on or directed to one side only

seep: a place where soil water reaches the surface slowly, bringing about wetland conditions

sepal: leaf-like component, segment or lobe of a calyx

sessile: stalkless as of a leaf or stigma

sheath: the lower, tube-shaped part of a leaf clasping the stem

shrub: a woody, perennial plant smaller than a tree lacking a trunk but growing several branches from the base

shrublet: small shrub

sorus (plural sori): a patch of spore-bearing receptacles on the lower surface of a fern frond

spathe: large, leaf-like bract that encloses some flowers during the bud stage

spike: an inflorescence consisting of sessile flowers along a simple, undivided axis or rachis

spikelet: a small spike made up of one or more flowers or florets covered by glumes as in grasses

spinescent: spine-tipped or having spines

spur: a slender, usually hollow extension of a flower part

staminode: a rudimentary, sterile or abortive stamen; a filament lacking an anther, sometimes colourful or petal-like

stellate: star-like, with extensions radiating from the centre

stigma: the receptor tip of a pistil

stipe: a stalk of a frond or stem of a seaweed or fungus; the stalk supporting a carpel

stipel: a secondary stipule at the base of a leaflet

stipule: a leaf-like or scale-like appendage of a leaf, usually positioned at the base of the petiole

stolon: a specialised stem or root producing separate new plants away from the mother plant, a runner which roots

stomata: gas exchange openings on green plant part surfaces

strigose: covered by short stiff or straight, appressed hairs

style: the stalk of a pistil linking the stigma to the ovary

subulate: narrowly linear or awl-shaped, tapering to a fine point

succulent: bearing thick, juicy or fleshy leaves or stems adapted for storing water

suffrutex: a perennial plant that is slightly woody only at its base

suture: a furrow where plant parts join, such as the seam of a seedpod

sympodial: an apparent main stem of a plant, composed of successive secondary axes repeatedly halted and replaced by successive new lateral growth, imitating a simple stem but zigzagging

synanthous: leaves appearing concurrent with flowers; compare hysteranthous

taxon (plural taxa): any group of organisms that is given a formal taxonomic name

tepal: component, unit or segment of a flower perianth, not differentiated into petals and sepals

terete: cylindrical or circular in cross-section

testa: outer coat of a seed

thyrse: an inflorescence type in which the main axis is a raceme, the secondary and later axes are cymes; a branching flower cluster in which the central axis is indeterminate and the lateral branches are determinate cymes

tomentose: covered with dense, matted, woolly hairs

translucent: semi-transparent, diffusing light but obscuring definite contours of an object

tuber: swollen underground storage stem or root

tubercle: a small, raised area or nodule on a plant surface

umbel: a flat-topped or rounded flower cluster in which the individual flower stalks arise from about the same point

uintjie: nutgrass, nutsedge or cormous, underground base of certain geophytes, some edible

villous: having long, soft hairs, often curved, but not matted

viscidium: a sticky pad-like gland, part of the rostellum that is joined to the pollinium of an orchid flower

zygomorphic: bilaterally symmetrical, as in flower structure, opposed to actinomorphic or radially symmetrical