Brunonia R.Br.

Scientific Description

Common name. Pincushions. Family Goodeniaceae (Brunoniaceae).

Habit and leaf form. Shrubs, or herbs. Annual, or perennial. Leaves basal (mostly), or basal and cauline. Plants with a basal concentration of leaves, or with neither basal nor terminal concentrations of leaves. Mesophytic, or xerophytic. Leaves alternate; spiral; petiolate; non-sheathing; simple; epulvinate. Leaf blades entire; linear, or obovate (to oblanceolate or spathulate); pinnately veined; cross-venulate. Leaves without stipules. Leaf blade margins entire. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present (very variable in hairiness); complex hairs present, or absent. Extra-floral nectaries absent (ass.). Stem anatomy. Secondary thickening absent, or developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Entomophilous. Pollination mechanism conspicuously specialized (involving a stylar modification for pollen presentation).

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes, or in heads. The terminal inflorescence unit cymose, or racemose. Inflorescences scapiflorous; terminal; scapes with a single terminal head, or numerous heads up to 35 mm diameter composed of shortly pedicellate cymes; with involucral bracts (green, surrounding a terminal head. Outer bracts ovate or narrowly ovate, apex acuminate and often reflexed. Inner bracts narrowly ovate to oblong and shorter); pseudanthial. Flowers subsessile, or sessile; bracteate (several hyaline bracts to each flower, elliptic to oblong); bracteolate (4, 3–4 mm long, scarious, glabrous); small to medium-sized; regular; 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present, or absent. Perianth with distinct calyx and corolla; (8–)10; 2 -whorled; isomerous, or anisomerous. Calyx present; 5; 1 -whorled; gamosepalous; blunt-lobed; tubular. Calyx lobes linear. Corolla present; 5; 1 -whorled; gamopetalous; lobed. Corolla lobes about the same length as the tube. Corolla tube not noticeably adaxially split. Corolla valvate; narrowly tubular; regular, or bilabiate (slightly); bright blue. Corolla lobes oblong (B), or linear (A). Androecial members definite in number. Androecium 5. Androecial members adnate (KC); all equal (ass.); coherent; 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5. Staminal insertion near the base of the corolla tube. Stamens all inserted at the same level; all more or less similar in shape (ass.); isomerous with the perianth; oppositisepalous (at the base of the corolla tube, epipetalous); all alternating with the corolla members. Anthers cohering (forming a tube); dehiscing via longitudinal slits; introrse; tetrasporangiate. Pollen shed in aggregates, or shed as single grains. Gynoecium 2 carpelled. The pistil 1–2 celled. Gynoecium syncarpous (KC); synstylovarious to eu-syncarpous; superior. Ovary unilocular to plurilocular; 1–2 locular (the septum incomplete above); sessile (ass.). Gynoecium stylate. Styles 1; bearing an ‘indusium’ beneath the stigma. Indusium cupular. Styles apical. Stigmas 1; 2 - lobed. Ovules in the single cavity 1 (attached basally on septum or ridge); ascending; non-arillate; anatropous.

Fruit and seed features. Fruit non-fleshy; indehiscent; capsular-indehiscent, or a nut. Seeds copiously endospermic. Endosperm oily. Seeds winged, or wingless. Cotyledons 2. Embryo straight.

Etymology. After Robert Brown (1773–1858).