Australian Biological Resources Study
Compiled by A.McCusker
imparipinnate: having an uneven number of pinnae, by virtue of having one terminal pinna. cf. paripinnate. > image <
incised: cut deeply, sharply and often irregularly (an intermediate condition between toothed and lobed).
included: enclosed, not protruding.
incrassate: thickened; of a pollen grain, with thickened margins around the apertures.
incumbent: of the orientation of an embryo, with the cotyledons lying face to face and folded downwards beside the radicle; of anthers, lying against the inner face of the filament.
incurved: bent or curved inwards or upwards; of leaf margins, curved towards the adaxial surface.
indefinite: variable in number; numerous; of stamens, more than twice as many as the petals or sepals; of an inflorescence, not terminating in a flower (i.e. having a continuing, terminal growing point).
indehiscent: not opening at maturity.
indeterminate: of an inflorescence, when the floral axis is not terminated by a flower, ie a racemose inflorescence. cf. monopodial.
indumentum: the epidermal appendages, e.g. hairs or scales, collectively. > image <
induplicate: folded inwards so that the outer faces of the margins are in contact.
indusium: tissue covering the sorus of a fern; a hollow pollen-cup surrounding the stigma in Goodeniaceae.
inferior: of an ovary, at least partly below the level of attachment of the other floral parts. cf. superior. > image <
inflexed: bent sharply upwards or forwards. cf. deflexed.
infraspecific: of lower taxonomic rank than species.
infructescence: the grouping or arrangement in which fruits are borne on a plant.
insectivorous: catching, and ostensibly feeding on, insects.
inserted (on): attached to; arising from.
integument: a covering; one of the outer layers of tissue of an ovule.
intercalary: between two points.
intercalary growth: extension or growth from an intercalary meristem, i.e. neither from the apex nor the base.
intercalary inflorescence: an inflorescence that either arises in an internodal position, or one originally terminal but ceasing to be so when vegetative growth subsequently resumes from the stem apex. > image <
internode: the portion of a stem between the level of insertion of two successive leaves or leaf pairs (or branches of an inflorescence).
interpetiolar: of stipules, between the petioles of two opposite leaves. cf. intrapetiolar. > image <
interrupted: of an inflorescence, having the flowers unevenly distributed along the axis, with conspicuous gaps.
interstaminal corona: in Asclepiadaceae, fleshy lobes, often connate into a tube, attached to the base of the staminal column in the interstaminal areas. see gynostegial corona.
intramarginal: situated inside but close to the margin, e.g. of a vein in a leaf.
intrapetiolar: between a petiole and the subtending stem. cf. interpetiolar. > image <
introduced: not indigenous; not native to the area in which it now occurs. cf. adventive, naturalised.
introrse: of anthers, dehiscing towards the centre of the flower. cf. extrorse. > image <
involucre: a group of bracts enveloping a condensed inflorescence; a layer of tissue enveloping particular structures, e.g. an archegonium in Bryophyta, sporangia in Hymenophyllaceae.
involucel: involucre of bractlets surrounding a secondary inflorescence such as the base of an umbellule.
involute: rolled inwards; of a leaf, with the margins rolled towards the adaxial surface. cf. revolute. > image <
irregular: see zygomorphic.
isobilateral (= isolateral): having structurally similar upper and lower surfaces. cf. dorsiventral.
isotype: a specimen which is a duplicate of the holotype, i.e. part of the same collection. cf. type.