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Kohautia Cham. & Schltdl.

Linnaea 4 p156 (1829)
Name Status

Scientific Description

Family Rubiaceae.

Habit and leaf form. Erect herbs, or shrubs (subshrubs). Herbs annual, or perennial. Young stems cylindrical. Helophytic, or mesophytic, or xerophytic. Leaves opposite, or whorled; sessile; connate (via the stipules), or not connate; gland-dotted, or not gland-dotted; simple; epulvinate. Leaf blades entire; one-veined, or pinnately veined; cross-venulate. Leaves with stipules. Stipules interpetiolar (adnate to the leaf base, forming a short sheath produced into a single lobe or with 1 to several fimbriae); with colleters (secreting mucilage), or without colleters. Leaf blade margins entire, or serrate. Leaves without a persistent basal meristem. Stem anatomy. Nodes unilacunar, or tri-lacunar. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Plants homostylous. Entomophilous. Pollination mechanism conspicuously specialized (with passive pollen presentation involving stylar modification), or unspecialized.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’, or solitary; in cymes, or in panicles, or in corymbs. The terminal inflorescence unit cymose. Inflorescences terminal, or axillary (rarely). Flowers small to medium-sized; regular; 4 merous, or 5 merous; cyclic; tetracyclic. Free hypanthium present, or absent (depending on interpretation). Perianth with distinct calyx and corolla; 8, or 10; 2 -whorled; the two whorls isomerous. Calyx 4, or 5; 1 -whorled; gamosepalous; lobed; open in bud; regular; persistent. Corolla 4, or 5; 1 -whorled; gamopetalous; valvate; tubular (tube cylindrical with 2 distinct widths), or hypocrateriform; regular; glabrous adaxially, or hairy adaxially (throat pilose); pale blue (in K. australiensis). Androecium 4, or 5. Androecial members adnate (to the corolla tube); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 4, or 5. Staminal insertion in the throat of the corolla tube. Stamens remaining included, or becoming exserted (rarely, then anther tips only); isomerous with the perianth; oppositisepalous. Anthers basifixed (or nearly so); dehiscing via longitudinal slits; introrse; tetrasporangiate. Pollen shed in aggregates, or shed as single grains; if aggregated, in tetrads. Gynoecium 2 carpelled. The pistil 2 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synstylovarious to eu-syncarpous; inferior. Ovary plurilocular; 2 locular. Gynoecium transverse. Epigynous disk present. Gynoecium stylate. Styles 1; simple; attenuate from the ovary, or from a depression at the top of the ovary; apical; shorter than the ovary at anthesis to much longer than the ovary at anthesis; not becoming exserted (the stigma overtopped by the anthers). Stigmas 1; 1 - lobed, or 2 - lobed (then lobes filiform, erect); wet type, or dry type; papillate, or non-papillate; Group II type and Group IV type. Placentation axile. Ovules 10–40 per locule (i.e. ‘numerous’, immersed in fleshy placenta); pendulous, or horizontal, or ascending; anatropous, or hemianatropous.

Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule (crustaceous). Capsules loculicidal (splitting between calyx lobes). Fruit 10–80 seeded (i.e. ‘numerous’ seeded). Seeds angular; endospermic, or non-endospermic. Endosperm ruminate, or not ruminate; if present, oily. Cotyledons 2. Embryo straight, or curved. Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Aluminium accumulation demonstrated, or not found.

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, and Queensland. Northern Botanical Province.

Additional characters Fruit rostrate (beak truncate, not prominent). Corolla lobes spreading.

H.R. Coleman, 8 September 2016

Taxonomic Literature

  • Halford, David A. 1992. Review of the genus Oldenlandia L. (Rubiaceae) and related genera in Australia.