- Scientific Name: Ophiorrhiza japonica Blume
- Ref: Bijdr. Fl. Ned. Ind.:978. 1826
- Synonyms:
- Ophiorrhiza acutiloba Hayata
- O. cavaleriei H.Lév.
- O. dimorphantha Hayata
- O. japonica f. plena T.Yamaz.
- O. labordei H.Lév.
- O. monticola Hayata
- O. nigricans H.S.Lo
- O. tashiroi Maxim.
- English Common Name: Japanese snake root
- Chinese Common Name: 蛇根草 shégēn∙cǎo, 日本蛇根草 Rìběn shégēn∙cǎo
- Japanese Common Name: サツマイナモリ [薩摩稲森] satsumainamori
- Family: Rubiaceae
- Genus: Ophiorrhiza
- Distribution: Fertile soil of ravines in forests; 100-2400 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangxi, S Shanxi?, Sichuan, Taiwan, NE Yunnan, Zhejiang [Japan, Vietnam].
- Photo: Gaoshancun, Zhejiang
Herbs, weak to ascending, to 60 cm tall, often drying flushed with purple or darkened; stems subterete to slightly compressed, glabrous or with 2 hirtellous or pilosulous lines. Leaves in subequal pairs; petiole 0.3-2(-3) cm, glabrous to hirtellous or puberulent; blade drying papery, ovate, elliptic-ovate, elliptic, elliptic-oblong, lanceolate, or narrowly lanceolate, 1-11 × 0.7-3.5 cm, glabrous to strigillose or hispidulous adaxially, glabrous to puberulent, hirtellous, or villosulous abaxially, base cuneate to obtuse, margins flat to crisped, apex acute to acuminate or rarely obtuse (to rounded, Ophiorrhiza nigricans); secondary veins 4-8 pairs; stipules triangular, 0.8-2 mm, glabrescent, acute to bifid, caducous sometimes leaving 1 to several thickened scars to 0.3 mm. Inflorescence congested-cymose to cymose, few to many flowered, puberulent to strigillose, pilosulous, or hirtellous; peduncle 0.5-5 cm (to 6 cm, O. nigricans); axes congested-cymose becoming helicoid; bracts lanceolate-linear, spatulate, or linear, 1-6 mm, sometimes glabrescent, persistent. Flowers distylous, on pedicels 1-2 mm. Calyx glabrous to densely puberulent or pilosulous; hypanthium subturbinate to oblate or subglobose, 0.8-1 mm, 5-ribbed; lobes triangular, 0.4-1.2 mm. Corolla white or pink, funnelform to tubular-funnelform, outside glabrous to puberulent or pilosulous and longitudinally winged, inside pilose near middle and pilosulous above middle through throat and sometimes onto lobes; tube 9-14 mm; lobes triangular to ovate, (1.5-1.8 mm, O. nigricans) 2.5-4 mm, dorsally with wing to 0.5 mm wide, apex rostrate. Capsules submitriform, 2.5-4 × 6.5-9 mm, pilosulous to glabrous. Fl. winter, fr. spring and summer. (Flora of China)