Botany Terms with Definitions

Term Definition
abaxial away from the axis, referring to the surface of an organ that is furthest from the axis in bud. cf. adaxial
abscission the normal shedding from a plant of an organ that is mature or aged. adj. abscissile
acaulescent without a stem, or with stem so short that the leaves appear basal
achene a dry, 1-seeded, indehiscent fruit formed from a superior ovary of one carpel. Used to describe the fruit of the Asteraceae formed from an inferior ovary, following the definition given by De Candolle; equivalent to the term cypsela
actinomorphic having radially arranged floral segments which are more or less equal in size and shape, referring to a flower, calyx or corolla. cf. zygomorphic
aculeate covered in prickles
acuminate tapering gradually to a protracted point. cf. attenuate
acute terminating in a distinct but not protracted point, the converging edges forming an angle of less than 90 degrees. cf. obtuse
adaxial towards the axis, referring to the surface of an organ that is closest to the axis in bud. cf. abaxial
adherent touching without organic fusion, referring to parts normally separate, e.g. floral parts of different whorls. cf. adnate, coherent, connate
adnate fused to an organ of a different kind, e.g. a stamen fused to a petal or an anther fused for its whole length to the filament. Also used to describe the type of anther in some eucalypts which is basifixed, immobile and about as wide as long. cf. adherent, coherent, connate
adpressed lying close to another organ but not fused to it. See appressed
adventitious arising in abnormal positions, e.g. roots arising from the shoot system, buds arising elsewhere than in the axils of leaves
alien belonging to another place
allomorphic with a shape different from the typical shape
alluvium deposits of earth, sand, etc., left by water flowing over land that is not permanently submerged
alternate borne singly and spaced around and along the axis, applied to leaves or other organs on an axis. Also used to describe the position of floral parts of different whorls on different radii, e.g. stamens with respect to petals. cf. opposite
amphibious capable of living on or in water or on drying soil. Frequently an amphibious plant has a different form in different habitats
amplexicaul clasping the stem
anastomosing connecting with one another, particularly applied to veins
ancipitous two-edged
androdioecious having male flowers and bisexual flowers on separate plants. cf. gynodioecious
androecium the male part of a flower; a collective term for the stamens of one flower
androgynous having male and female flowers in distinct parts of the same inflorescence
andromonoecious having male flowers and bisexual flowers on the same plant. cf. gynomonoecious
angiosperm a division of seed plants with the ovules borne in an ovary. cf. gymnosperm
annual completing the full cycle of germination to fruiting within a single year and then dying. cf. biennial, perennial
annular arranged in or forming a ring
anther that part of the stamen in which the pollen is produced
anthesis the period that a flower is open, i.e. between the opening of the bud and the onset of withering
anthocarp a false fruit consisting of the true fruit and the base of the floral whorls
antrorse directed upwards. cf. retrorse
apiculum a short, sharp, flexible point. adj. apiculate
appressed pressed closely to another organ but not united
aquatic a plant living in or on water for all or a substantial part of its life span. cf. terrestrial
arborescent resembling a tree; applied to non-woody plants attaining tree height and to shrubs tending to become tree-like in size
aril a fleshy to hard structure which develops from the funicle or ovule after fertilisation and encloses all or part of the seed. adj. arillate
aristate having a stiff, bristle-like tip
aristulate having a small, stiff, bristle-like tip; a diminutive of aristate
articulate jointed; usually fracturing easily at the nodes or point of articulation into segments or articles
ascending arched upwards in the lower part and becoming erect in the upper part. cf. decumbent, procumbent
attenuate tapering gradually. cf. acuminate
auricle an ear shaped appendage at the base of a leaf, leaflet or corolla lobe; or an ear-like outgrowth at the base of the sheath of some grasses and other monocots. adj. auriculate, also used to describe a leaf base which has lobes on both sides of the petiole
autotrophic self feeding, not depending on parasitism or entirely on organic matter. cf. heterotrophic
awn a slender, bristle-like projection, e.g. from the back or tip of the glumes and lemmas in some grasses and on the fruit of some Geraniaceae. adj. awned
axil the angle between one part of a plant and another part, e.g. a branch and a leaf. adj. axillary
axis main stem of the plant or the flower-bearing portion of an inflorescence or the ovule-bearing structure in ovaries with axile placentation
barbate bearded, having tufts of hairs
barbellae short, stiff, hair-like bristles. adj. barbellate
basal arising from or positioned at the base
beak a prominent terminal projection, especially of a carpel or fruit. adj. beaked
berry a fleshy or pulpy indehiscent fruit with the seed(s) embedded in the fleshy tissue of the pericarp
biconvex convex on both sides
biennial completing the full cycle of germination to fruiting in more than one, but not more than two years, and then dying
bifoliolate having two leaflets
bipinnate 2-pinnate; twice pinnately divided
bipinnatisect 2-pinnatisect; twice pinnatisectly lobed
biserrate doubly serrate; with smaller regular, asymmetric teeth on the margins of larger teeth
bisexual having both sexes, as in a flower bearing both fertile anthers and a fertile ovary. cf. unisexual
biternate twice ternately divided
blade lamina; part of the leaf above the sheath or petiole
bract a leaf-like structure, usually different in form from the foliage leaves, associated with an inflorescence or flower. adj. bracteate
bracteole a small bract-like structure borne singly or in a pair on the pedicel or calyx of a flower. adj. bracteolate
broadly having a length:breadth ratio between 6:5 and 1:1; if the ratio is less then the shape is described as very broadly. cf. narrowly
bulb a modified underground axis that is short and crowned by a mass of usually fleshy, imbricate scales. adj. bulbous
bulbil a small bulb produced on aerial parts such as a leaf axil or an inflorescence
burr a partial infructescence, often prickly or rough, as in some Amaranthaceae and Asteraceae
buttress supporting outgrowth from base of a tree trunk as in some Rhizophoraceae and Moraceae
caducous falling early before associated organs are mature. cf. deciduous, persistent
caespitose growing densely in tufts; having short, closely packed stems
calcareous composed of or containing lime or limestone
callus see callosity
callosity a thickened, raised mass of hardened tissue, often formed after an injury but sometimes a normal feature, e.g. the glandular wart-like structures on the labellum of some orchids, or in grasses, the hardened, usually hairy base of the dispersal unit, usually a floret or whole spikelet. pl. calli, callosities. adj. callose
calyptra hooded or lidded
calyx the outermost floral whorl usually consisting of sepals or a calyx tube and calyx lobes. adj. calycine
calyx lobe one of the free upper parts of the calyx which may be present when the lower part is united into a tube
calyx tube the tubular, often cup shaped or bell shaped, fused part of the calyx when it is free from the corolla. cf. floral tube
campanulate a 3-dimensional shape; bell shaped
canescent grey or white in colour due to a covering of short, fine grey or white hairs
capitate growing together in a head. Also meaning head-like as in some stigmas
capitulum a dense cluster of sessile, or almost sessile, flowers or florets
capsule a dry fruit formed from two or more united carpels and dehiscing at maturity to release the seeds. adj. capsular
carpel an organ, generally believed to be leaf-derived, which bears 1 or more ovules, a stigma and sometimes a style. Often much modified in a syncarpous ovary. adj. carpellary
caryopsis the grass fruit, which has the seed coat united with the ovary wall
caudate having a narrow, tail-like appendage
caulescent having an obvious aerial stem
cauliflorus of flowers and fruits, borne on old wood
cauline borne on the aerial part of a stem. cf. radical
chartaceous papery
chasmogamous describing flowers in which pollination takes place while the flower is open. cf. cleistogamous
ciliate fringed with hairs
ciliolate minutely ciliate
cilium a straight, usually erect hair on a margin or ridge. pl. cilia
circinnate spirally coiled, with the tip innermost
circumscissile opening by a transverse line around the circumference
cladode the modified photosynthetic stem of a plant whose foliage leaves are absent or much reduced. cf. phyllode, phylloclade
clavate a 3-dimensional shape; club shaped; thickened at one end
claw the conspicuously narrowed basal part of a flat organ
cleistogamous describing flowers which are self-pollinating and set fertile seed without the flower opening. cf. chasmogamous
climber growing more or less erect by leaning or twining around another structure
cline a character gradient over a geographical area where one or several morphological features gradually change over a part or over the whole distribution area. adj. clinal
coccus one of the segments of a distinctly lobed fruit which becomes separate at maturity. Sometimes called a mericarp. pl. cocci
coherent touching without organic fusion, referring to parts normally together, e.g. floral parts of the same whorl. cf. adherent, adnate, connate
column a structure formed by the united style, stigma and stamen(s), as in Asclepiadaceae, Stylidiaceae and Orchidaceae
complicate conduplicate q.v.
compound consisting of two or more anatomically or morphologically equivalent units
compressed flattened
concolorous uniformly coloured, as in upper and lower surfaces. cf. discolorous
conduplicate folded together lengthwise
cone a reproductive structure composed of an axis (branch) bearing sterile bract-like organs and seed or pollen bearing structures. Strictly refers to the Gymnospermae or Lycopodiales but frequently used for the fruiting spike in Casuarinaceae and flowering and fruiting structure in some Proteaceae
conic a 3-dimensional shape; cone shaped, attached at the broader end
connate fused to another organ of the same kind. cf. adherent, adnate, coherent
connective the tissue separating two lobes of an anther
conspecific within or belonging to the same species
contiguous neighbouring parts being in contact but not fusing
convolute an arrangement of petals in a bud where each has one side overlapping the neighbouring petal
cordate a 2-dimensional shape; heart shaped in outline, i.e. having the base broad and distinctly notched
coriaceous leathery
corm a very short, broad, firm-fleshed, subterranean stem which produces aerial stems, leaves and flowers. adj. cormous
cormel a miniature corm produced in leaf axils
corolla the floral whorl inside the calyx, usually consisting of petals or a corolla tube and corolla lobes. adj. corolline
coroniform crown shaped, as in the pappus of Asteraceae which may be coroniform when the membranous scales are connate
corymb an inflorescence, usually a raceme, in which the flowers, through unequal pedicels, are in one horizontal plane. adj. corymbose
costa a thickened, linear ridge or the midrib of the pinna in ferns. adj. costate
cotyledon the primary (“seed”) leaf, each seedling having one or two, rarely more
crenate with obtuse or rounded teeth which either point forwards or are perpendicular to the margin
crenulate minutely crenate
crisped very strongly undulate; margins which are wavy in a vertical plane, the waves themselves with secondary waves. cf. undulate
crustaceous hard, thin and brittle
culm the aerial stem of grasses, sedges, rushes and other monocots, bearing the cauline leaves and the inflorescence
cultivar cultivated variety; 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 a 2-dimensional shape; obtriangular, i.e. wedge shaped
cusp an elongated, usually rigid, acute point. cf. mucro
cuspidate somewhat abruptly and sharply concave and constricted into a cusp. cf. mucronate
cuspidulate constricted into a minute cusp. cf. cuspidate
cylindric a 3-dimensional shape; tubular or rod shaped with a length:breadth ratio of 2:1 to 3:2. cf. narrowly, broadly
cymbiform boat shaped
cyme an inflorescence in which each flower, in turn, is formed at the tip of a growing axis, further flowers being formed on branches arising below. adj. cymose
decorticate to remove the bark, rind or husk from; to strip of its bark; to come off as a skin
decumbent spreading horizontally with the apex growing upwards, referring to stems. cf. ascending, procumbent
decurrent having the leaf base prolonged down the stem as a winged expansion or rib
decussate having paired organs with successive pairs at right angles to give four rows
deflexed bent downwards
dehiscent breaking open at maturity to release the contents. cf. indehiscent
dendritic branching from a main stem or axis; resembling the branching of a tree
dentate with sharp, spreading, rather coarse teeth standing out from the margin
denticulate finely dentate
depressed flattened as if pressed down from the top or end; applied to 2 or 3-dimensional shapes, e.g. ovate and obovate or ovoid and obovoid which have a length:breadth ratio of less than 2:3
dichasium a cyme in which the branches are opposite and approximately equal. pl. dichasia. adj. dichasial
dichotomous divided almost equally into two parts
digitate having parts arranged like the fingers on a hand
dimorphic with two forms, e.g. having stamens of two different lengths or having two kinds of leaves. cf. uniform
dioecious having male and female unisexual flowers on different plants. cf. monoecious
disc the usually disc shaped receptacle of the head in Asteraceae. Also the fleshy nectariferous organ which is sometimes annular or lobed and developed usually between the stamens and ovary. Also used for the enlarged style-end in Proteaceae
disc floret a tubular 4 or 5-toothed or lobed floret on the disc of an inflorescence, i.e. head of Asteraceae
disciform describing an inflorescence, i.e. head of Asteraceae with central disc florets and marginal female florets which have a reduced inconspicuous slender tubular corolla without a ligule; or an inflorescence with only such reduced female florets. cf. discoid, radiate
discoid resembling a disc; a solid structure with two convex faces. Used in the Asteraceae to describe a head which has only disc florets present. cf. disciform, radiate
discolorous having two colours, e.g. the lower leaf surface distinctly different in colour from the upper. cf. concolorous
distal end of any structure farthest from the point of attachment. cf. proximal
distichous two-ranked, arranged in two diametrically opposite rows
divaricate widely spreading
drupe a 1-celled fruit with one or two seeds enclosed by a stony layer (endocarp) which is embedded in succulent tissue (mesocarp) surrounded by a thin outer skin (epicarp). adj. drupaceous
echinate bearing stiff, stout, prickly hairs
eglandular without glands. cf. glandular
ellipsoid a 3-dimensional shape; elliptic in outline and with a length:breadth ratio between 3:2 and 2:1. cf. narrowly, broadly
elliptic a 2-dimensional shape; oval in outline and with a length:breadth ratio between 3:2 and 2:1. cf. narrowly, broadly
elongate lengthened; stretched out
emarginate having a broad, shallow notch at the apex. cf. retuse
endemic having a natural distribution confined to a particular geographical region
endocarp the innermost layer of the fruit wall, derived from the innermost layer of the carpel wall. cf. exocarp, mesocarp, pericarp
entire without any incisions or teeth
ephemeral short-lived
epicalyx a whorl of bracts, just below or joined to the calyx, resembling a second calyx
epicormic attached to the corm
epipetalous borne on the petals
epiphyte a plant growing on, but not parasitic on, another plant, e.g. some Orchidaceae. adj. epiphytic
erect upright; perpendicular
exocarp the outermost layer of the fruit wall, derived from the outermost layer of the carpel wall. Sometimes called epicarp. cf. endocarp, mesocarp, pericarp
exserted protruding beyond some enclosing organ, e.g. referring to stamens which project beyond the corolla or perianth, or to valves which extend beyond the rim of a capsular fruit. Sometimes the stamens are not actually longer than the corolla or perianth but are exserted due to the spreading of the segments. cf. included
exstipulate without stipules. cf. stipulate
extrorse turned outwards or away from the axis. In the case of anthers, dehiscing longitudinally outwards. cf. introrse, latrorse
eye a distinctly pigmented area, e.g. a brightly coloured spot, usually near the centre of the standard of some flowers of Papilionaceae; also refers to the scale-like leaves and dormant axillary buds of a tuber
falcate sickle shaped
fascicle a cluster. adj. fasciculate
ferruginous rust coloured
fertile provided with functional sexual parts which are capable of fertilisation and seed production. cf. sterile
filament the stalk of a stamen below the point of attachment to the anther
filiform thread-like
fimbriate fringed
flaccid limp and weak
flexuose zig-zagging, often referring to a stem
floccose covered with tufts of soft woolly hairs that usually rub off readily
floral tube the part of the flower enveloping an ovary and formed by the fusion of the calyx tube, corolla tube and sometimes stamen filaments and receptacle. Variously referred to elsewhere as calyx tube, perigynium or hypanthium
floret one of the small individual flowers of the Asteraceae or the reduced flower of the grasses, including the lemma and palea
flower the sexual reproductive structure of the angiosperms, typically consisting of gynoecium, androecium and perianth or calyx and/or corolla and the axis bearing these parts
foliar pertaining to a leaf
-foliolate used with a number prefix to denote the number of leaflets
foliose leafy
follicle a dry fruit, derived from a single carpel and dehiscing along one suture
forb See herb
frond the leaf of a fern or cycad
fruit seed-bearing structure formed from the ripened ovary after flowering
fusiform a 3-dimensional shape; spindle shaped, i.e. is circular in cross-section and tapering at both ends
gametophyte a plant bearing sexual organs; in ferns a small discrete plant, very different from the sporophyte, also known as the prothallus. cf. sporophyte
geophyte a plant with an underground storage organ, e.g. a tuber, bulb or rhizome, and with an annually renewed aerial shoot
glabrescent becoming glabrous
glabrous without hairs
gland a secretory structure, e.g. a nectary, extra-floral nectary or a gland tipped, hair-like or wart-like organ. adj. glandular. cf. eglandular
glaucous blue-green in colour, with a whitish bloom
globular a 3-dimensional shape; spherical or orbicular; circular in outline
glume one of the two bracts at the base of the grass spikelet, called the lower and upper glumes, due to their position on the rachilla. Also used in Apiaceae, Cyperaceae for the very small bracts on the spikelet in which each flower is subtended by one floral glume and in which there are often several empty glumes at the base. adj. glumaceous
gneiss a metamorphic rock composed, like granite, of quartz, feldspar or orthoclase, and mica but distinguished from it by its foliated or laminated structure
gymnosperm a member of the division of seed plants with the ovules and hence seeds, borne on a sporophyll or cone scale, and not borne in an ovary. cf. angiosperm
gynoecium the female part of a flower; a collective term for the carpel or carpels
gynomonoecious having female flowers and bisexual flowers on each individual plant. cf. andromonoecious
gypsum hydreous calcium sulphate, resembling chalk
habit the growth form of a plant, comprising its size, shape, texture and stem orientation
halophyte a plant adapted to living in highly saline habitats; a plant that accumulates high concentrations of salt in its tissues. adj. halophytic
hastate with a pair of basal lobes which flare outwards; refers to a flat organ, most commonly a leaf
herb a plant which is non-woody or woody at the base only, the above ground stems usually being ephemeral. adj. herbaceous, q.v.
herbaceous herb-like; often applied to bracts, bracteoles or floral parts that are green and soft in texture
hermaphrodite bisexual, bearing flowers with both androecium and gynoecium in the same flower. adj. hermaphroditic
heterogamous bearing separate male and female flowers or florets in an inflorescence or flower head, e.g. some Asteraceae in which the ray florets may be neuter or unisexual and the disk florets may be bisexual. cf. homogamous
heteromorphous with two or more distinct forms. cf. homomorphous
heterosporous producing spores of 2 sizes, the larger giving rise to megagametophytes (female), the smaller giving rise to microgametophytes (male). Applied to the ferns and fern allies. cf. homosporous
hirsute with long and rather coarse or stiff hairs, the hairs being less rigid and erect than when referred to as hispid
hispid with stout, rigid or bristly, erect hairs
hoary covered with a greyish layer of very short, closely interwoven hairs
homochromous of the same colour; usually used to describe those Asteraceae that bear a 1-coloured inflorescence, i.e. head, the disc and ray florets being the same colour. cf. heterochromous
homogamous bearing one kind of flower unit rather than separate male and female flower units, e.g. some Asteraceae where all of the florets in an inflorescence or flower head are bisexual. cf. heterogamous
homomorphous uniform, with only one form. cf. heteromorphous
homosporous producing spores of the same size and sex. Applied to the ferns and fern allies. cf. heterosporous
hybrid the offspring of the sexual union of plants belonging to different taxa
hydrophilous water loving; requiring water in order to be fertilized, referring to many aquatic plants
hypanthium see floral tube
imbricate closely packed and overlapping. cf. valvate
imparipinnate pinnately compound with a single terminal leaflet and hence with an odd number of leaflets. cf. paripinnate
incised cut jaggedly with very deep teeth
included not protruding beyond some enclosing organ, e.g. stamens which do not project beyond the corolla or to valves which do not extend beyond the rim of a capsular fruit. cf. exserted
incurved curved inward; curved towards the base or apex
indefinite numerous and variable in number
indehiscent not opening or splitting to release the contents at maturity. cf. dehiscent
indumentum the type of hairiness commonly found on external parts of plants. cf. vestiture
indurate hardened, often the hardening developed only at maturity
indusium tissue covering the sorus of a fern. Also used for the modified style end or pollen-cup of some Goodeniaceae (including Brunoniaceae). adj. indusiate
inferior a flower in which the ovary is fused with the floral tube and the sepals, petals and stamens are inserted above most of the ovary. cf. superior
inflated enlarged and hollow except in the case of a fruit which may contain a seed. cf. swollen
inflexed bent or turned downwards, towards the axis
inflorescence the arrangement of flowers in relation to the axis and to each other
internode the part of an axis between two successive nodes, joints or point of attachment of the leaves
intricate entangled
introduced not indigenous; not native to the area in which it now occurs
introrse turned inwards or towards the axis. In the case of anthers, dehiscing longitudinally inwards. cf. extrorse, latrorse
involucre a large bract or whorl of bracts surrounding a flower or an entire inflorescence
involute with the margins inrolled on the upper (adaxial) surface, referring to a leaf or other flat organ
ironstone the name given to various hard iron-ores containing admixtures of silica, clay, etc
jugate of a pinnate leaf; having leaflets in pairs
juvenile young or immature, used here for leaves formed on a young plant which are different in morphology from those formed on an older plant
kaolin a fine white clay produced by the decomposition of feldspar
keel a boat shaped structure, with a prominent longitudinal ridge, or, in the Papilionaceae, the part of the corolla formed by the fusion of the lower edge of the two abaxial petals. adj. keeled. cf. standard, wing
labellum the usually modified, adaxial, inner perianth segment of the orchid flower which by torsion of the ovary is usually abaxial
laciniate fringed; having slender, narrow, pointed lobes
lamina the usually flattened blade of a leaf or frond. Also used here for the limb, the flattened part of the ligulate floret of Asteraceae. pl. laminae
lanate covered with long hairs which are loosely curled together like wool
lanceolate lance shaped, much longer than wide, the widest point below the middle
laterite a red, porous, ferruginous rock
latex a milky, clear or sometimes coloured sap of diverse composition found in some plants
latrorse turned sideways, i.e. not towards or away from the axis. In the case of anthers, dehiscing longitudinally on the side. cf. extrorse, introrse
leaflet one of the ultimate segments of a compound leaf
lemma the lower of two bracts of a grass floret, usually enclosing the palea, lodicules, stamens and ovary
lenticel a lens shaped dot or pit on young bark, through which gaseous exchange may occur
lenticular shaped like a biconvex lens
liane a woody climbing or twining plant
lignotuber a woody, usually underground, rootstock often giving rise to numerous aerial stems
ligulate small and tongue shaped or with a little tongue shaped appendage or ligule, q.v. Also applied to the florets of the Asteraceae which have a single small tongue shaped corolla lobe
ligule outgrowth from the inner junction of the grass leaf sheath and blade, often membranous, sometimes represented by a fringe of hairs. Also a small, membranous, triangular organ on the adaxial side of the fertile leaf base in Isoetes or the narrow, upper part of a reduced petal in some Sterculiaceae or the single corolla lobe of a floret of Asteraceae. cf. ligulate
limb the expanded portion of a flat organ above the claw. Also used here for the expanded portion of the calyx tube or the corolla tube, e.g. in the Apiaceae and Solanaceae
linear a 2-dimensional shape: narrowly rectangular with parallel sides and a length:breadth ratio of at least 12:1
linguiform tongue shaped
lobe a usually rounded or pointed projecting part, usually one of two or more, each separated by a fissure or sinus. The terms calyx lobe, corolla lobe and floral lobe are used here for the projections of the calyx, corolla or floral tube. cf. segment
loose lax or not crowded; with distant or scattered units
lyrate pinnately lobed, with the terminal lobe the largest and the laterals progressively smaller towards the base
mallee a growth habit in which several to many woody stems arise separately from a lignotuber; usually applied to certain low-growing species of Eucalyptus
mangrove coastal trees or shrubs subject to periodic tidal inundation, rarely occurring in fresh water, often with modified roots, often viviparous; plant community in tidal stretches of the mouth of some rivers containing mangrove species
margin (in leaves); the edge of the leaf blade
megasporangium the sporangium containing megaspores. cf. microsporangium
megaspore the large spore which may develop into the female gametophyte in heterosporous ferns and fern allies. cf. microspore
mericarp a 1-seeded portion of an initially syncarpous fruit which splits apart at maturity, e.g. in the Apiaceae. Sometimes called a coccus, q.v.
-merous used with a number prefix to denote the basic number of the 3 outer floral whorls, e.g. a 5-merous flower may have 5 sepals, 10 petals and 15 stamens
mesocarp the middle layer of the fruit wall derived from the middle layer of the carpel wall. cf. endocarp, exocarp, pericarp
microsporangium the sporangium containing microspores. cf. megasporangium
microspore a small spore which gives rise to the male gametophyte in heterosporous pteridophytes. Also used by some authors for a pollen grain. cf. megaspore
midvein the main vascular supply of a simple leaf blade or lamina
minni-ritchi bark reddish bark exfoliating in narrow, curled strips. Usually only applied to certain species of Acacia or Eucalyptus
monoecious having both male and female unisexual flowers on the same individual plant. cf. dioecious
monopodial with a persistent terminal growing point producing many lateral organs progressively. cf. sympodial
monotypic of a genus with one species or a family with one genus; in general, applied to any taxon with only one immediately subordinate taxon
mucilage a soft, moist, viscous secretion. adj. mucilaginous
mucous slimy
mucro a stiff or sharp, short projection of the midvein abruptly terminating an organ. cf. cusp
mucronate abruptly tipped with a mucro, accompanied or not by a small amount of leaf tissue. cf. cuspidate, muticous
mucronulate with a very small mucro; a diminutive of mucronate
muricate with numerous short hard outgrowths. cf. papillose
muriculate with numerous minute hard outgrowths; a diminutive of muricate
muticous blunt, lacking awn or point. cf. mucronate
narrowly having a length:breadth ratio between 3:1 and 6:1; if the ratio is more than 6:1 then the shape is described as very narrowly, except in the case of very narrowly oblong which is termed linear
native a plant indigenous to the locality
nectariferous having one or more nectaries
nectary a secretory organ producing nectar; commonly in a flower, sometimes on leaves, fronds or stems
nut dry indehiscent 1-celled fruit with a hard pericarp
ob- prefix meaning inversely or opposite to
obconic a 3-dimensional shape; cone shaped, attached at the narrower end
obcordate a 2-dimensional shape; broad and notched at the tip; heart shaped but attached at the pointed end
obdeltate a 2-dimensional shape; deltate with the broadest part at the apex
oblong a 2-dimensional shape; rectangular with a length:breadth ratio between 3:2 and 2:1. cf. narrowly, broadly
obovate a 2-dimensional shape: similar to ovate but attached at the narrower end and with a length:breadth ratio between 3:2 and 2:1. cf. narrowly, broadly
obpyramidal a 3-dimensional shape; resembling a 4-sided pyramid attached at the apex with the square base facing away from the attachment
obpyriform a 3-dimensional shape; resembling a pear which is attached at the narrower end. cf. pyriform
obspathulate a 2-dimensional shape; resembling a spoon attached at the broadest end and with a length:breadth ratio between 3:2 and 2:1. cf. spathulate
obtriangular a 2-dimensional shape; triangular, attached at the apex and with a length:breadth ratio between 3:2 and 2:1. cf. triangular
obtrullate a 2-dimensional shape; resembling a trowel blade with the broadest axis above the middle and a length:breadth ratio between 3:2 and 2:1. cf. narrowly, broadly, trullate
obtuse blunt or rounded at the apex, the converging edges separated by an angle greater than 90 degrees. cf. acute
-oid suffix denoting a 3-dimensional shape
operculum a lid or cover becoming detached at maturity by abscission, e.g. in Eucalyptus, a cap covering the bud and formed by fusion or cohesion of sepals and/or petals. adj. operculate
opposite describing leaves or other organs which are borne at the same level but on opposite sides of the stem; of floral parts, on the same radius. cf. alternate
orbicular of circular outline
order a classificatory rank intermediate between class and family, i.e. a group of families believed to be closely related or sometimes a single family with no apparent close relatives
orifice an opening or aperture such as that of a cup shaped receptacle or the summit of a leaf sheath in grasses and sedges
ovary the basal portion of a carpel or group of fused carpels, enclosing the ovule(s)
ovate a 2-dimensional shape; resembling a section through the long axis of an egg, attached near the broader end and with a length:breadth ratio between 3:2 and 2:1. cf. narrowly, broadly
ovoid a 3-dimensional shape; egg shaped; ovate in outline
ovule the organ in the ovary which becomes a seed after fertilisation. adj. ovular
ovulode a sterile reduced ovule borne on the placenta, commonly occurring in Myrtaceae
palate a raised appendage on the lower lip of a corolla which partially or completely closes the throat
palea the upper of the two bracts of a grass floret, usually enclosing the lodicules, stamens and ovary. pl. paleae. adj. paleal. cf. lemma
paleochannel paleozoic? Fossilised soils
pallid pale
palmate describing a leaf which is divided into several leaflets which arise from the same point. adj. palmately
panduriform a 2-dimensional shape; fiddle shaped
panicle a compound raceme; an indeterminate inflorescence in which the flowers are borne on branches of the main axis or on further branches of these. adj. paniculate
papilionaceous pea-flowered; flowers which are zygomorphic with imbricate petals, one broad upper one, two narrower lateral ones and two narrower lower ones, the latter usually coherent or connate by their margins; the flowers of Papilionaceae
papilla a small protuberance on the surface of an organ being an extension of one epidermal cell. pl. papillae. adj. papillose. cf. muricate
pappus a tuft (or ring) of hairs, bristles or scales borne above the ovary and outside the corolla in Asteraceae and possibly representing the calyx; often persisting as a tuft of hairs on a fruit. adj. pappose
paripinnate pinnate with an even number of leaflets and without a terminal leaflet. A tendril may be terminal on the leaf. cf. imparipinnate
-partite divided almost to the base into segments, the number of segments given as a prefix
patent spreading, diverging from the axis almost at right angles
pectinate pinnatifid with narrow segments set closely like the teeth of a comb
pedicel the stalk of an individual flower. In a single-flowered inflorescence, may refer to a peduncle, or both peduncle and pedicel when undifferentiated. Also used here for the stalk of a spikelet in Poaceae. adj. pedicellate
peduncle the stalk of an inflorescence. adj. pedunculate
pellucid clear, transparent or nearly so
peltate attached to the stalk at a point within the margin, i.e. on the lower surface
pendulous drooping; of ovules, attached at the top of the ovary and hanging downwards from an apical placenta
penniveined pinnately veined
perennial with a life span extending over more than two growing seasons. cf. annual, biennial
perfoliate with basal lobes united and encircling the stem, commonly referring to a leaf where the stem runs through the leaf base
perianth the outer floral whorl or whorls of a monocotyledonous flower, sometimes divisible into outer and inner perianth segments. Sometimes used by other authors to describe the floral whorl of a dicotyledonous flower when it is uncertain if the whorl is calycine or corolline in origin or used as a collective term for calyx and corolla
pericarp the wall of a fruit developed from the ovary wall. Composed of the exocarp, mesocarp and endocarp
persistent remaining attached; not falling off. cf. caducous
petal free segment of the corolla. adj. petaline. cf. lobe
petiolar pertaining to the petiole
petiole the stalk of a leaf. adj. petiolate
petiolule the stalk of a leaflet. adj. petiolulate
phylloclade a cladode which is green and leaf-like with the true leaves represented by scales
phyllode a leaf whose blade is much reduced or absent and whose petiole has assumed the functions of the whole leaf. adj. phyllodineous, cf. cladode
piliferous bearing or producing hair, usually referring to an organ with the apex having long, hair-like extensions
pilose with slightly stiffened distinct hairs ascending from the surface
pindan vegetation consisting of a lower storey of grasses, a middle storey of dense Acacia thickets and a sparse upper layer of trees up to 15 m high
pinna a primary segment of the blade of a compound leaf or frond. pl. pinnae
pinnate with the same arrangement as a feather; divided into pinnae; once-compound
pinnatifid lobed approximately halfway to midrib. If divided almost to the midrib, then described as deeply pinnatifid or pinnatisect, q.v.
pinnatisect lobed almost to base or midrib
pinnule a leaflet of a bipinnate leaf
placenta the region within the ovary to which ovules are attached
plano- a prefix meaning level; flat
plicate folded like a fan
plumose like a feather; with fine hairs arising laterally from a central axis
pneumatophore modified root which allows gaseous exchange in mud-dwelling shrubs, e.g. mangroves
pod a dry 1-many-seeded dehiscent fruit. Commonly applied to the fruits of Caesalpiniaceae, Mimosaceae and Papilionaceae
polygamous with unisexual and bisexual flowers on the same or on different individuals of the same species
polymorphic with many morphological variants
procumbent trailing or spreading along the ground but not rooting at the nodes, referring to stems. cf. ascending, decumbent, erect
prostrate lying flat on the ground
proximal end of any structure closest to the point of attachment. cf. distal
pruinose with a frosty surface; having a thick, waxy, powdery coating
pseudocarp a false fruit, largely made up of a fleshy receptacle
pteridophyte a vascular plant which reproduces by spores; the ferns and fern allies
puberulent, puberulous covered with very short fine straight erect hairs
pubescent covered with short, soft hairs
pulvinus an enlargement below the base of a leaf or leaflet in which changes of turgidity enable the leaf or leaflets to droop or fold. Also a glandular swelling in the axils of the inflorescence axis and primary branches of some grasses. adj. pulvinate
punctate marked with dots, e.g. the clear-coloured oil glands of a leaf of Rutaceae and Myrtaceae
punctulate marked with minute dots; a diminutive of punctate
pungent ending in a rigid, sharp point
pyrene the “stone” or “pit” of a drupe, consisting of the hardened endocarp and seed
pyriform a 3-dimensional shape; resembling a pear, attached at the broader end. cf. obpyriform
quartzite an extremely compact, granular rock, consisting essentially of quartz
raceme an indeterminate inflorescence with a simple, elongated axis and pedicellate flowers. adj. racemose
rachilla the main axis of a grass spikelet
rachis the main axis of the spike or other inflorescence of grasses; the axis of a pinna in a bipinnate leaf
radiate arranged around a common centre; used here especially to describe an inflorescence of Asteraceae with marginal, female or neuter, ligulate ray-florets and central, perfect or functionally male, tubular, disc florets. cf. disciform, discoid
ray the marginal portion of the inflorescence of Asteraceae and Apiaceae when distinct from the disc. Also, the axis or branches of a compound umbel in some Apiaceae, Cyperaceae and Apiaceae, Loranthaceae
receptacle the region at the end of a pedicel or on an axis which bears one or more flowers. In the Asteraceae the receptacle may be quite large. adj. receptacular
recurved curved outward or downward
reflexed bent or turned downward
reniform a 2-dimensional shape; kidney shaped in outline
resinous producing resin; often sticky
resupinate twisted through 180 degrees
reticulate forming a network or reticulum
retrorse bent or directed downwards or backwards. cf. antrorse
retuse with a very blunt and slightly notched apex. cf. emarginate
revolute with the margins inrolled on the lower (abaxial) surface
rhizome a creeping stem, usually below ground, consisting of a series of nodes and internodes with adventitious roots. adj. rhizomatous
rhizophore a stilt-like extension of the stem which branches into roots on contact with the substrate
rhombic a 2-dimensional shape; diamond shaped in outline with the broadest axis in the middle and with a length:breadth ratio between 3:2 and 2:1. cf. quadrate-rhombic, narrowly
rib a distinct vein or linear marking, often raised as a linear ridge
rosette a tuft of leaves or other organs resembling the arrangement of petals in a rose, ranging in form from a hemispherical tuft to a flat whorl. adj. rosetted, rosulate
rostrate beaked; the apex narrowed into a slender, usually obtuse point
rostrum a beak-like extension
rotate wheel shaped; applied to a corolla with a very short tube and a broad upper part which is flared at right angles to the tube. cf. salverform
rugose deeply wrinkled
rugulose finely wrinkled; a diminutive of rugose
saccate pouched
sagittate arrow shaped, with a pair of large, acute or rounded, usually overlapping lobes
samara an indehiscent, winged, dry fruit
scabrous rough to the touch
scandent climbing
scape the stem-like flowering stalk of a plant with radical leaves. adj. scapose
scapigerous with a scape
scarious dry and membranous
schist a crystalline rock whose component minerals are arranged in a more or less parallel manner
schistose laminated; having a formation resembling a schist
schizocarp a usually dry fruit which splits longitudinally into indehiscent or tardily dehiscent parts (mericarps or cocci)
sedge a plant of the family Apiaceae, Cyperaceae
segment a free or almost free part or subdivision of an organ. Calyx and corolla segments are called sepals and petals respectively. In the case of undifferentiated dicotyledonous flowers, the segments are called floral segments. cf. lobe
sepal free segment of the calyx. adj. sepaline
septum a partition or cross wall. A term for the sterile structure separating the seeds in a mature fruit of Banksia. pl. septa. adj. septate
sericeous silky; covered with close-pressed, fine, straight silky hairs
serrate toothed so as to resemble a saw; with regular, asymmetric teeth pointing forward
sessile without a stalk
seta a bristle or stiff hair. pl. setae. adj. setose, setaceous
setiform bristle shaped
setulose with minute bristles; a diminutive of setose
sheathing clasping or enveloping the stem
shrub a woody plant usually less than 5 m high and many-branched without a distinct main stem except at ground level. cf. undershrub
silicula a broad, dry, usually dehiscent fruit derived from two or more carpels which usually dehisce along two sutures and which has a persistent partition after dehiscence. cf. siliqua
siliqua a silicula which is at least twice as long as broad
simple not divided, e.g. applied to a leaf not divided into leaflets. cf. compound
sinuate with deep wave-like indentations in a horizontal plane along the margin. cf. repand
skeletal (soils) composed of
solitary usually used to describe flowers which are borne singly, and not grouped into an inflorescence
sorus a discrete aggregate of sporangia in ferns. pl. sori
spadix a spike-like inflorescence with an unbranched, usually thickened axis and small embedded flowers, the whole structure often surrounded by a spathe. pl. spadices
spathe a large bract ensheathing an inflorescence or its peduncle. adj. spathaceous
spatheate like or with a spathe
spathulate spoon shaped; broad at the tip and narrowed towards the base
spiculate spikelet-bearing
spike an unbranched inflorescence of sessile flowers or spikelets. adj. spicate, spiciform
spikelet the grass flowerhead, generally composed of 2 glumes and one or more florets. Also used for the small spike-like inflorescence or inflorescence units commonly found in Apiaceae, Cyperaceae and Restionaceae
spine a stiff, sharp, pointed structure, formed by modification of a plant organ. adj. spinose
spinescent ending in a spine; modified to form a spine
spinulose with small spines over the surface
sporangium a spore bearing structure used here particularly for ferns, fern allies and gymnosperms. pl. sporangia. adj. sporangial
sporocarp a stalked fruit case, formed from modified sporophylls, containing sporangia or spores, e.g. in Marsilea
sporophyll a leaf or bract which bears or subtends sporangia in the fern allies, ferns and gymnosperms
spur a pouch-like short to slender, usually hollow extension of some part, usually of a flower
squarrose with spreading rigid processes, e.g. the tips of bracts or leaves
stamen one of the male organs of a flower, consisting typically of a stalk (filament) and a pollen-bearing portion (anther). adj. staminal, staminate
staminode a stamen without pollen; often lacking an anther, often reduced in size, sometimes elaborated in structure. adj. staminodial
standard the usually adaxial petal in the flower of Papilionaceae. cf. keel, wing
stellate star shaped, usually referring to hairs with radiating branches
stem the main axis or a branch of the main axial system of a plant, developed from the plumule of the embryo and typically bearing leaves
sterile lacking any functional sexual parts which are capable of fertilisation and seed production. cf. fertile
stigma the usually papillate or glandular part of the style which receives the pollen. adj. stigmatic
stilt root a supporting root arising from the stem some distance above the ground as in some mangroves, sometimes also known as a prop root
stipe a stalk or support such as the petiole of a frond or the stalk of an ovary or fruit
stipel stipule-like appendage at the base of a leaflet (in unifoliolate leaves, inserted on the petiole, not on the stem). pl. stipellae. adj. stipellate
stipitate having a stalk or stipe, usually of an ovary or fruit. cf. sessile
stipule one of a pair of leaf-like, scale-like or bristle-like structures inserted at the base or on the petiole of a leaf or phyllode. adj. stipulate, cf. exstipulate
stolon the creeping stem of a rosetted or tufted plant, giving rise to another plant at its tip, or in Drosera a vertical underground stem connecting the tuber with the above ground parts and bearing adventitious roots. adj. stoloniferous
striae parallel longitudinal lines or ridges. adj. striate
strobilus a cone-like structure formed from sporophylls or sporangiophores. pl. strobili
style the usually narrowed, elongated part of a carpel or group of fused carpels, between the ovary and stigma
sub- a prefix meaning nearly or almost, as in subcapitate or subequal
subspecies taxon differing in minor morphological characters such as size or shape of parts, and either partially or completely isolated by means of geographic, ecologic or other barriers
substrate underlying rock
subulate narrow and tapering gradually to a fine point
succulent fleshy, juicy, soft in texture and usually thickened
sulcate grooved; furrowed
superior a flower in which the ovary is free and mostly above the level of insertion of the sepals, petals and stamens. cf. inferior
suture a line, mark or groove marking a natural division or union of parts of an organ
swollen enlarged and solid. cf. inflated
sympetalous having united petals
synangium an organ composed of united sporangia, divided internally into cells, each containing spores. pl. synangia
syncarp an ovary of two or more united carpels with a single style. adj. syncarpous
taxon a classificatory group of any rank, e.g. a family, genus, species or any infraspecific category. pl. taxa
tendril a slender organ formed from a modified stem, leaf or leaflet which, by coiling around objects, supports a climbing plant
tepal a segment of the perianth, which is not differentiated into calyx and corolla; a sepal or petal
terete circular in cross-section
terminal at the apex or distal end
ternate in threes
terrestrial growing on ground; not aquatic
tessellate with colours or shades arranged in small squares so as to give a chequered appearance
testa a seed coat
tomentose covered with not very long cottony hairs, more or less felted together, shorter and less dense than lanate
transverse broader than long; applied to 2 or 3-dimensional shapes, e.g. elliptic and oblong or ellipsoid and obovoid which have a length:breadth ratio of less than 5:6
trapeziform a plane, asymmetric shape with four straight sides of unequal length
tree a woody plant usually over 5 m high and with an unbranched lower axis
triad a group of three; used to describe the 3-flowered umbels found in some Loranthaceae
triangular a 2-dimensional shape; 3-angled and 3-sided with a length:breadth ratio between 3:2 and 2:1. cf. narrowly, broadly, deltate
tribe a category intermediate in rank between subfamily and genus
trichotomous divided almost equally into three parts
tridentate three toothed
trifoliate having three leaves
trifoliolate a leaf having three leaflets
trifurcate with 3 terminal, long lobes
trigonous obtusely 3-angled; triangular in cross-section with plane faces
tripinnate pinnately compound three times, with pinnate pinnules
triquetrous acutely 3-angled; triangular in cross-section with concave faces and each corner projected outwards so that the organ has three distinct longitudinal ridges
trullate a 2-dimensional shape; resembling a trowel blade, i.e. with 4 straight sides with the axis broadest below the middle and a length:breadth ratio between 3:2 and 2:1. cf. narrowly, broadly, obtrullate
truncate with an abruptly transverse end as if cut off
tuber a stem, usually underground, enlarged as a storage organ and with minute scale-like leaves and buds or “eyes”. Some monocotyledons e.g. Thysanotus develop thickened roots called tuberous roots. adj. tuberous
tubercle a wart-like protuberance. adj. tuberculate
tuft a densely packed cluster arising from an axis. adj. tufted
turbinate top shaped; inversely conic
turgid swollen
typical variant the variant of a species to which belongs the type specimen of that species
umbel an inflorescence in which the pedicels originate from one point on top of the peduncle and are usually of equal length. adj. umbellate
uncinate hooked at the apex
undershrub subshrub; a small, usually sparsely branched woody shrub less than 1 m high. cf. shrub
undulate with an edge or edges wavy in a vertical plane; may vary from weakly to strongly undulate or crisped. cf. crisped
unifoliolate a compound leaf which has been reduced to a single, usually terminal leaflet
uniform with one form, e.g. having stamens of a similar length or having one kind of leaf. cf. dimorphic
uniseriate arranged in one line or at one level
unisexual with one sex only, either bearing the anthers with pollen, or an ovary with ovules, referring to a flower, inflorescence or individual plant. cf. bisexual
urceolate urn shaped
valvate meeting without overlapping, usually referring to sepals or petals in bud. cf. imbricate
valve one of the parts produced by the splitting of a capsule when ripe or a part of the specialised opening of a capsular fruit
variant any definable individual or group of individuals which may or may not be regarded as representing a formal taxon after scrutiny
variegate diverse in colour or marked with irregular patches of different colours
variety a classificatory rank below that of subspecies
vein a strand of vascular tissue
velum a flap of tissue covering the sporangium in Isoetes
velutinous covered with a close silky coating of short fine hairs which are erect and of even length. cf. sericeous
venation the arrangement of veins in a leaf
vernation the arrangement of young leaves or fronds in a bud or at a stem apex, e.g. erect or circinnate, q.v.
verrucose warty
verticillate whorled; arranged in one or more whorls
vesicle a small bladdery sac or cavity filled with air or fluid. adj. vesicular
vestigial the remaining trace or remnant of an organ which was probably fully developed in some evolutionary predecessor
vestiture covering; the type of hairiness, scaliness or other covering commonly found on the external parts of plants. cf. indumentum
villous with long, soft hairs sometimes lying on the surface, finer than in pilose
virgate with a broom-like habit, more or less densely branched with stiff, more or less erect branches, leaves usually small
viscid sticky on the surface; coated with a thick, syrup-like secretion
viviparous having the seeds germinate on the parent plant or, in the case of ferns, having new plants develop on the fronds
whorl a ring-like arrangement of similar parts arising from a common point or node
wing any flat, often membranous expansion or flange, e.g. on a seed, stem or one of the two lateral petals of a papilionaceous flower or one of the petal-like sepals of Polygalaceae. cf. keel, standard
xerophyte a plant which naturally grows in dry regions and is often structurally modified to withstand dry conditions
zygomorphic having only one plane of symmetry, usually the vertical plane, referring to a flower, calyx or corolla. cf. actinomorphic.
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