Description from Flora of China
Herbs 30-50 cm tall. Rhizomes rough, nodose, with fibrous roots. Stem solitary. Leaves usually 4, crowded apically on stem; leaf blade broadly elliptic, ovate, or obovate, 10-25 × 6-16 cm, membranous, abaxially subglabrous except sparsely strigose along veins, adaxially sparsely strigose, secondary veins 7-9 on both sides of midvein, almost flat on both surfaces, base obtuse to narrowly cuneate, margin roughly and acutely dentate, apex entire or deeply 2-lobed with lobes 5-6 cm. Inflorescence a pedunculate, corymbose cyme, 9-15 cm, glabrous; bracts alternate, lanceolate, 1.5-2.5 cm, margin denticulate. Sterile flowers with sepals 3 or 4, greenish to blue, ovate to orbicular, subequal, ca. 1.4 cm wide. Fertile flowers usually nodding; pedicel rough, 0.5-1.5 cm. Calyx blue or slightly red; tube ca. 4 mm; lobes 5, ovate to suborbicular, 5-8 mm, apex subacute to cuspidate. Petals 6-8, blue or slightly red, obovate, suborbicular, or broadly orbicular, 1-1.4 cm wide. Stamens very numerous; filaments and anthers slightly blue; anthers ellipsoid, apex obtuse. Ovary incompletely 5-loculed. Styles terete, 5-6 mm, apex deeply 5-cleft. Capsule subglobose, ca. 1 cm in diam. Seeds brown (immature). Fl. Jun-Jul.
Deinanthe caerulea is similar to the Japanese species D. bifida Maximowicz. However, D. caerulea differs in having leaves usually 4, crowded at the stem apex, both surfaces with sparse, simple hairs, and flowers in a corymbose cyme.
* Moist forests in valleys; 700-1600 m. W Hubei.