Perennial herb 0.015-0.12 m tall, erect to decumbent from creeping and rooting base, with stems numerous to few, initially unbranched below inflorescence, later branched above. Stems narrowly and ± equally 4-winged, with black glands on the wings and sometimes elsewhere; internodes 12-65(-80) mm, longer than leaves. Leaves sessile; lamina 6-40 ´ (3-)7-14(-20) mm, elliptic or narrowly ovate to narrowly oblong or rarely suborbicular, paler beneath, thickly to thinly chartaceous; apex rounded to obtuse or rarely subacute, margin usually crisped-undulate, base rounded to cordate-subamplexicaul; venation: 3(4) pairs of main laterals from lower quarter of midrib, tertiary reticulation rather dense; laminar glands pale, dense, medium to small; intramarginal glands black close, irregular in size. Inflorescence 7-c. 40-flowered, from 1-3 nodes, with flowering branches ascending to horizontal from up to 6 nodes, the whole cylindric to subcorymbiform, lax; pedicels 1-2.5 mm; bracts and bracteoles 2-4 mm long, lanceolate, entire, with (0-)2-8 black glands. Flowers 12-17 mm in diam., stellate; buds ellipsoid, obtuse. Sepals 5, subequal, 3-5.5 ´ 1-1.8 mm, narrowly elliptic to lanceolate, acute to acuminate, entire, erect in bud and fruit; veins (3)5-7, when 5 the outer pair branched; laminar glands punctiform, all pale or nearly always (3-)6-20(-28) black; intramarginal glands black, few or absent, rarely with terminal black gland. Petals 5, bright yellow, nearly always tinged red dorsally, (5-)7-10 ´ 3-4 mm, c. 2-2.5 ´ sepals, obovate-oblanceolate, entire; laminar glands black, punctiform, few or absent; marginal glands black, up to 6, scattered, or absent. Stamensc. 25-40, '3'-fascicled, longest (4.5-)5-8 mm, c. 0.75-0.9 ´ petals. Ovary 3-locular, 2-3.5 ´ 1-1.5 mm, narrowly ovoid to narrowly ellipsoid; styles 3, free, 3-4 mm, 1-1.3 ´ ovary, spreading; stigmas narrowly capitate. Capsule 5-8 ´ 3.5-4 mm, c. 1.65 ´ sepals, ovoid; valves with longitudinal linear vittae. Seeds yellow-brown, 0.6-0.8 mm, cylindric, not carinate or appendiculate; testa linear-foveolate.