Oldenlandia L.

Scientific Description

Family Rubiaceae.

Habit and leaf form. Herbs. Plants succulent, or non-succulent. Annual, or perennial (rarely). Young stems tetragonal. Helophytic, or mesophytic, or xerophytic. Leaves opposite; petiolate to 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 leaf bases, membranous, mostly produced into triangular lobes, margins usually fimbriate); with colleters (secreting mucilage), or without colleters. Leaf blade margins entire, or serrate. Leaves without a persistent basal meristem. Domatia recorded, or not recorded; represented by pits, or pockets, or hair tufts. 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 (protandrous). Plants homostylous, or heterostylous (not in Australia). Entomophilous. Pollination mechanism conspicuously specialized (with passive pollen presentation involving stylar modification), or unspecialized.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’, or solitary; when solitary, axillary; in cymes (lax), or in panicles, or in corymbs, or in fascicles. The terminal inflorescence unit cymose. Inflorescences terminal, or axillary. Flowers minute to small; regular; 4 merous; cyclic; tetracyclic. Free hypanthium present, or absent (depending on interpretation). Perianth with distinct calyx and corolla; 8; 2 -whorled; the two whorls isomerous. Calyx 4; 1 -whorled; polysepalous (epigynous), or gamosepalous (forming a short, free tube); lobed; open in bud; turbinate, globose or obloid, rarely ribbed; regular; persistent. Corolla 4; 1 -whorled; gamopetalous; valvate; hypocrateriform, or funnel-shaped; regular; white, or purple, or blue, or pink. Androecium 4. Androecial members adnate (to the corolla tube); free of one another; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 4. Staminal insertion in the throat of the corolla tube. Stamens becoming exserted, or remaining included; isomerous with the perianth; oppositisepalous; filantherous. Anthers dorsifixed; 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; partly inferior, or inferior (4/5 to 9/10 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; becoming exserted, or not becoming exserted (if both anthers and stigma included then anthers overtopped by the stigma). Stigmas 1; mostly 2 - lobed (bifid), or 1 - lobed; when simple, capitate (or rarely conical); wet type, or dry type; papillate, or non-papillate; Group II type and Group IV type. Placentation axile, or apical (near base of septum by short stalk). Ovules 2–20 per locule (i.e. ‘2 to numerous’ on fleshy, globose or obloid placentas); pendulous, or horizontal, or ascending; anatropous, or hemianatropous.

Fruit and seed features. Fruit non-fleshy; dehiscent; a capsule (crustaceous). Capsules loculicidal. Fruit mostly numerous seeded. Seeds obconic, truncate obconoidal, meniscoid, scutelliform, cerebriform or obovoid; endospermic, or non-endospermic. Endosperm ruminate, or not ruminate; when 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.

Etymology. After Henrik Bernhard Oldenland (d.1761), Danish botanist; curator of the botanical garden at the Cape of Good Hope c.1695.