Vietnamese Balm

Description

Herbs erect, 30-50cm tall. Stems glabrous or pilose, stramineous, purple-brown with age. Petiole 0.5-3.5 cm, narrowly winged; leaf blade ovate to elliptic-lanceolate, 3-9 — 1-4cm, sparsely minutely hispid, adaxially sparsely resinous glandular, base cuneate decurrent, margin serrate, apex acuminate. Spikes 2-7 — 1.3cm, secund; verticillasters many flowered; bracts broadly ovate to oblate, ca. 4 — 4mm, subglabrous to puberulent, sparsely resinous glandular abaxially, glabrous adaxially, ciliate or ciliolate, apical mucro to 2mm. Pedicel ca. 1.2mm, subglabrous, densely white pubescent. Calyx ca. 1.5mm, pilose, sparsely glandular outside, glabrous inside; teeth triangular, anterior longer, needlelike, ciliate. Corolla purplish, ca. 4.5mm, villous outside, sparsely glandular on posterior side; throat pilose, ca. 1.2mm wide; upper lip emarginate; middle lobe of lower lip semicircular, lateral lobes arcuate, shorter than middle lobe. Anthers purple-black. Style included. Nutlets yellow-brown, oblong, ca. 1mm. Fl. Jul-Oct, fr. Oct-Jan. Hills, waste areas, sunny terraces, riverbanks, forests; 0-3400 m