Sida arsiniata R.M.Barker

Scientific Description

Herb or shrub, with hairy stems. Leaves 12-70 mm long, 3-25 mm wide, not lobed; margins crenate; hairy, with stellate hairswith scales absent, Sessile glands absent; stipules present and persistent to older leaves or present but early deciduous (only visible on youngest leaves), 8-10 mm long. Perianth clearly of two whorls (calyx and corolla), the corolla obvious and prominent. Pedicel present, 7-15 mm long; indumentum present, with stellate hairs present, with scales absent. Epicalyx (extra segments or 'bracteoles' immediately below the calyx) absent. Calyx green, 6-13 mm long, the lobes fused half or more of their length, Sessile glands absent, simple hairs (without tubercle bases) absent, stellate hairs present, tubercle-based simple hairs absent, gland-tipped hairs absent, scales absent, Terminal appendages absent, number of ribs absent. Corolla yellow, 5-7 mm long, glabrous. Indumentum (outside) Sessile glands absent. Stamens many, united and arising from a staminal tube around the style; filaments present, 1-2.2 mm long; anthers 0.3-1 mm long, indumentum absent (anthers glabrous). Staminodes absent, appendages absent. Ovary hairs and scales absent (ovary quite glabrous); style 1, 2.8-4 mm long, with four or numerous style branches or lobes, mostly glabrous, wing absent. Fruits indehiscent and splitting into sections (schizocarps), length-width ratio more or less as long as wide, mericarps wrinkled, hairs and scales absent, Sessile glands absent; apex distinctly flat-topped; prickles absent (except perhaps a terminal awn); terminal awns or spines absent; calyx persistent to mature fruit, not accrescent; carpels 12; seeds per loculus 1. Flowering time May, July, August or September. Distribution Botanical Province Eremaean, IBRA Bioregion Pilbara.