Description from Flora of China
E. macrostemon Handel-Mazzetti.
Herbs 50-100 cm tall. Stems purple, white pubescent on grooves. Petiole 0.8-2.5 cm, narrowly winged; leaf blade ovate to broadly ovate, 2-6 × 1-3 cm, adaxially pilose, abaxially impressed glandular, white pubescent on veins, base rounded to broadly cuneate, margin crenate or crenate-serrate, entire near base, apex short acuminate. Spikes 2-7 cm, secund; verticillasters 8-flowered; bracts circular, ca. 5 × 5 mm, apex abruptly spinescent, spines to 2 mm, abaxially white villous, yellow glandular, purplish, glabrous adaxially, margin ciliate. Pedicel ca. 1 mm. Calyx tubular, ca. 2.5 mm, white villous outside; teeth subulate, subequal, apex spinescent, margin ciliate. Corolla rose-purple, ca. 6 mm, white villous outside, glandular at apex, throat to 2 mm wide; upper lip emarginate, margin villous; lower lip slightly spreading, middle lobe oblong, apex usually mucronate; lateral lobes arcuate. Anthers dark purple. Nutlets dark brown, oblong, ca. 1 mm, minutely tuberculate. Fl. and fr. Sep-Nov.
Hilly thickets, forests, streamsides, riverside grasslands; 200-1200 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Sichuan, Zhejiang [Japan, Vietnam (cultivated)].