Plants 3-50 cm tall, glabrous, or pubescent with short falcate hairs on stem and short glandular hairs in inflorescence. Rhizomes with a tuberous thickening at apex. Leaves 2-7 cm long, 1.4-4.5 cm wide, ovate to broadly ovate, less commonly orbicular ovate, apex acute to very short acuminate, base broadly cuneate to subcordate, but most commonly truncate or rounded, margins subentire to occasionally prominently dentate. Flowering pedicels ascending or erect, flowers clustered at anthesis and opening before elongation of raceme axis, pubescent. Nectary wholly within floral tube and inconspicuous. Fruit 1.6-2.7 mm long, 0.5-1.2 mm thick, clavate or obovate, tapering smoothly to pedicel, unilocular and 1-seeded, without ribs or sulci, but pedicel extending as a shallow groove along upper surface. Fruiting pedicel and mature fruit 3.5-7.8 mm long. 2n=22. Flowers Jul-Sep (-Oct); fruit Aug-Nov.

ILAN: Nanhutashan, Ohwi 3938. HSINCHU: Tapachienshan, Shimizu 20264. TAICHUNG: Chika, Huang & Hsieh 7164. NANTOU: between Tienchih & Yunhai, Kao 5861. CHIAYI: Yushan, Ying 1461. TAITUNG: Takuanshan, Peng 11753. HUALIEN: Hohuanshan, Boufford et al. 19320.

Distribution: China, NW Vietnam, NE and NW Burma, Assam, India, westward along the south face of the Himalaya to NE Afghanistan; disjunct in S India. Cool, moist places in mountainous areas; 2,000 (1,500 m in S India) to 4,000 m.

Circaea alpina is an inbreeding complex of six geographically or ecologically separated subspecies, but with areas of overlap between two or more subspecies in parts of the range. These subspecies form a reticulate pattern of morphologically intergrading populations, some of which are separated only by seemingly minute differences. Other subspecies, were it not for numerous intermediate plants, appear so dissimilar that it would be easily justifiable to recognize them as separate species, as has often been done in the past. One subspecies is in Taiwan.