Microtoena megacalyx C. Y. Wu

Herbs. Stems 30-150 cm, densely fine puberulent, subglabrous or glandular puberulent at apex. Petiole to 11 cm; leaf blade ovate, 5-14 × 3.5-10 cm, subglabrous, densely glandular puberulent on veins adaxially, sparsely minutely hispid abaxially, base truncate-cuneate, attenuate into winged petiole, margin mucronate crenate-serrate, apex abruptly acuminate. Cymes dichotomous, 5-15-flowered, usually in terminal panicles ca. 11 cm; peduncle 1-4 cm; bracts leaflike, lanceolate. Calyx campanulate, 5-6 × 3-4 mm, glandular puberulent; teeth triangular, 2-3 mm, long setaceous, capitate glandular, hirsute; fruiting calyx to 12 × 5 mm, netted; teeth ca. 3 mm, hooked, posterior tooth ca. 4.5 mm. Corolla yellowish to white, ca. 2.5 cm; tube straight, slender, ca. 1.5 cm, densely puberulent, throat abruptly dilated; upper lip nearly straight; middle lobe of lower lip subcircular; lateral lobes subtriangular, wider, reflexed. Filaments puberulent. Nutlets black-brown, triquetrous, obovoid, base acute, 1.5-2.1 mm, 1-1.2 mm in diam., smooth, glabrous. Fl. Aug, fr. Sep.

Guizhou, Yunnan.

* Broad-leaved forests, grassy slopes near streams, streamsides in forests; 1500-2200 m.

Microtoena megacalyx là một loài thực vật có hoa trong họ Hoa môi. Loài này được C.Y.Wu mô tả khoa học đầu tiên năm 1959.

大萼冠唇花（学名：Microtoena megacalyx），为唇形科冠唇花属下的一个植物种。