imbricate: of perianth parts, having the edges overlapping in the bud. cf. valvate.

imparipinnate: having an uneven number of pinnae, by virtue of having one terminal pinna. cf. paripinnate.

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.

induplicate: folded inwards so that the outer faces of the margins are in contact.

indurated: hardened.

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.

inflexed: bent sharply upwards or forwards. cf. deflexed.

inflorescence: the group or arrangement in which flowers are borne on a plant.

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.

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.

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.

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.

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.

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.

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juvenile: of leaves, formed on a young plant and different in form from the adult leaves.

karyoevolution: evolutionary change in the chromosome set, expressed as changes in number and gross structure of the chromosomes; (more broadly), evolutionary relationships between taxa as indicated by karyotype differences.

karyotype: the gross morphology of the chromosome set, described in terms of number, length, centromere position, etc.

keel: a ridge like the keel of a boat; in Fabaceae, a boat-shaped structure formed by fusion of the two anterior petals of a flower.

keeled: of leaves, petals or bracts, folded and ridged along the midrib.

Kingdom (= regnum): the most inclusive taxonomic rank recognised by the International Code of Botanical Nomenclature (some authors have used the informal rank of Domain above that of Kingdom).

kwongan: low sand heath or sand plain sclerophyllous vegetation common in south-western W.A.

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Last updated on 13 May 1999.

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