Psychotria L.

Scientific Description

Family Rubiaceae.

Habit and leaf form. Small trees, or shrubs, or lianas, or herbs (rarely). Young stems cylindrical. Self supporting, or climbing. Helophytic, or mesophytic, or xerophytic. Leaves opposite; petiolate; connate (via the stipules), or not connate; gland-dotted, or not gland-dotted; simple; epulvinate. Leaf blades entire; pinnately veined; cross-venulate. Leaves with stipules. Stipules interpetiolar (membranous, free or connate into a tubular cap); with colleters (secreting mucilage); caducous. Leaf blade margins entire, or serrate. Leaves without a persistent basal meristem. Domatia recorded; represented by pits, or pockets, or hair tufts. Leaf anatomy. Hairs present, or absent. 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 heterostylous (filaments and style short or long). Entomophilous. Pollination mechanism conspicuously specialized (with passive pollen presentation involving stylar modification), or unspecialized.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes, or in heads. Inflorescences simple, or compound (cymes sometimes arranged in bracteate spikes, panicles or corymbs). The terminal inflorescence unit cymose. Inflorescences terminal, or axillary; with involucral bracts, or without involucral bracts. Flowers small; regular; 4–6 merous; cyclic; tetracyclic. Free hypanthium present, or absent (depending on interpretation); campanulate to globular. Perianth with distinct calyx and corolla; 8–12; 2 -whorled; the two whorls isomerous. Calyx 4–6; 1 -whorled; gamosepalous; entire, or lobed; open in bud; regular; persistent. Corolla 4–6; 1 -whorled; gamopetalous; valvate; tubular, or funnel-shaped; regular; hairy adaxially (hairy in throat, lobes thickened at apex); white. 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 midway down the corolla tube, or 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 as single grains. Gynoecium 2(–4) carpelled. The pistil 2(–4) celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synstylovarious to eu-syncarpous (depending on interpretation of stigmatic area); inferior. Ovary plurilocular; 2(–4) locular. Gynoecium transverse. Epigynous disk present. Gynoecium stylate. Styles 1; 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. Stigmas 1, or 2–4 (if stigmatic area interpreted as separate stigmas); 1 - lobed, or 2(–4) - lobed (if stigma interpreted as single and branched, the branches linear); wet type, or dry type; papillate, or non-papillate; Group II type and Group IV type. Placentation axile. Ovules 1 per locule; ascending; anatropous, or hemianatropous.

Fruit and seed features. Fruit fleshy; indehiscent; a drupe. The drupes with one stone, or with separable pyrenes (then 2(-4) pyrenes). Fruit 1–4 seeded. Seeds hemispherical; endospermic. Endosperm ruminate, or not ruminate; oily. Cotyledons 2. Embryo straight, or curved. Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Aluminium accumulation demonstrated.

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, Queensland, and New South Wales. Northern Botanical Province. X = 11.