Perennial herb (0.3-)0.5-1.5 m tall, erect to ascending from creeping and rooting base, with woody taproot, the basal branches numerous, diffuse, upper branches few, ascending or spreading-ascending or usually absent, the whole plant except inflorescence rather densely crisped-pubescent or (leaves) puberulous. Stems green to reddish (below), sometimes 2-lined and ancipitous in upper parts of inflorescence, otherwise terete; internodes mostly exceeding leaves. Leaves sessile, all pairs connate; lamina 10-45 x 10-30 mm, broadly elliptic to broadly oblong or obovate, subconcolorous, herbaceous, not glaucous, plane, spreading; apex rounded, margin plane, base usually with acute to obtuse or rarely rounded sinus between pairs; venation: 3 pairs of laterals, curved-ascending from lower c. 0.3 of midrib; tertiary reticulation dense, plane, not bullate/impressed; laminar glands pale, dense near margin, sparse near centre, not prominent and occasionally a few black, scattered; intramarginal glands black, sparse or absent. Inflorescence c. 10-100-flowered from 1-3 nodes, densely curved-corymbiform to rounded-pyramidal, becoming monochasial after second flower, sometimes with flowering branches from up to 4 nodes, the whole then laxly cylindric to obconic; pedicels (2-)3-6 mm; bracts not auriculate; bracteoles linear-triangular, black-glandular-ciliate or with some or all marginal glands sessile. Flowers c. 15-17 mm in diam.; buds ellipsoid, obtuse. Sepals 3-5 x 1-1.7 mm, subequal to unequal, elliptic to oblong or rarely ovate, acute to subacuminate, with margin gland-fringed; veins 5, branched and reticulating towards margin and distally; laminar glands pale and/or black, striiform to (mostly) punctiform, scattered; marginal glands black, prominent or on very short cilia. Petals 'clear butter yellow', tinged or veined red, 8-9(-10) x c. 2-2.5 mm, narrowly oblanceolate, rounded, without apiculus; laminar glands pale, punctiform to shortly linear, very sparse or absent, and occasionally black, few, distal; marginal glands black, few or in short dense row, distal. Stamensc. 35-40, clearly 3-fascicled, longest (6-)7-8 mm, c. 0.8 x petals; anther gland amber. Ovary c. 2.5 x 1.8 mm, narrowly ovoid; styles 3, 4.5-5 mm long, c. 2 x ovary, widely spreading-incurved. Capsule 4.5-6 x 2.5-4 mm, ovoid-pyramidal to ovoid, 1.3-2 x sepals, enclosed by petals twisting together. Seeds yellow-brown, 0.4-0.5 mm long; testa finely scalariform.