Description from Flora of China
Mananthes acutangula (H. S. Lo & D. Fang) C. Y. Wu & C. C. Hu.
Herbs 50-100 cm tall. Stems sharply 4-angled and slightly winged, sulcate, glabrous. Petiole ca. 1.3 mm, pubescent; leaf blade elliptic to rarely broadly elliptic, 8.5-28 × 5-12.5 cm, glabrous, secondary veins 13-15 on each side of midvein, base rounded to attenuate and decurrent onto petiole, margin subentire, apex acute. Spikes terminal or axillary in upper leaf axils, 3.5-14 cm, interrupted, unbranched or branched, with 1 flower per node; bracts triangular, 2-3 mm, glabrous, margin ciliate; bracteoles ca. 2.5 mm, glabrous, margin ciliate. Calyx ca. 5 mm, outside densely puberulent, 5-lobed almost to base; lobes lanceolate, apex acute. Corolla light greenish yellow with purplish dots on lower lip, 2-2.2 cm, outside pubescent; limb as long as tube; lower lip as long as upper lip, 3-lobed, lobes ovate, ca. 2 mm, and apex rounded; upper lip ca. 9 mm, apex emarginate. Staminal filaments ca. 7.5 mm, glabrous; anther thecae ca. 2.5 mm, superposed, lower one minutely spurred at base. Ovary glabrous; style ca. 2 cm, basal portion pubescent. Capsule clavate, ca. 2 cm. Seeds ovate in outline, ca. 1.2 × 1.3 mm. Fl. Nov-Jan, fr. Apr-May.
● Forests on limestone hills; 500-700 m. Guangxi, Guizhou.