Sida petrophila F.Muell.

Scientific Description

Herb or shrub, with hairy stems. Leaves 12-40 mm long, 5-15 mm wide, not lobed; margins crenate or serrate; hairy, with stellate hairswith scales absent, Sessile glands absent; stipules present and persistent to older leaves, 7-15 mm long. Perianth clearly of two whorls (calyx and corolla), the corolla obvious and prominent. Pedicel present, 3.2-9 mm long; indumentum present, with stellate hairs present, with scales absent. Epicalyx (extra segments or 'bracteoles' immediately below the calyx) absent. Calyx green, 6.5-10 mm long, the lobes fused less than half 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, 6-10 mm long, hairs or scales present, simple hairs (without tubercle bases) present, stellate hairs present, tubercle-based simple hairs absent, gland-tipped hairs absent, scales absent. Indumentum (outside) Sessile glands absent. Stamens many, united and arising from a staminal tube around the style; filaments present, 1-1.5 mm long; anthers 0.4-0.6 mm long, indumentum absent (anthers glabrous). Staminodes absent, appendages absent. Ovary hairs and scales absent (ovary quite glabrous); style 1, 5.5-6.2 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 or scales present, simple hairs (without tubercle bases) absent, stellate hairs present, Sessile glands absent, tubercle-based simple hairs absent, gland-tipped hairs absent, scales absent; apex distinctly flat-topped; prickles absent (except perhaps a terminal awn); terminal awns or spines present; calyx persistent to mature fruit, not accrescent. Flowering time August or September. Distribution Botanical Province Eremaean or South-West, IBRA Bioregion Yalgoo, Murchison, Coolgardie, Avon Wheatbelt and Esperance.