Glossary of Terms

    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