Herbs perennial. Roots fibrous. Rhizomes horizontal, elongate. Stems creeping or ascending, often branched, 5--20 cm, with a line of multicellular villous hairs. Leaves all cauline, sessile; leaf sheath 2--4 mm, with a line of dense, multicellular villous hairs; proximal leaf blades elliptic, 2--4 × 0.7--1.3 cm, glabrous, apex acute; distal leaf blades ovate, ca. 10 mm. Flowers 1--3, in fascicles in leaf axils; pedicel ca. 3 cm, with transparent, membranous leaf sheath near base, jointed at middle, mostly straight in fruit, sometimes slightly curved. Sepals narrowly ovate, ca. 3.5 mm. Petals blue or pink, orbicular. Fertile stamens 3; filaments sparsely red torulose villous; staminodes 3; antherodes sagittate. Capsule ovoid-ellipsoid, 4--5 × ca. 2 mm. Seeds ca. 4 per valve, uniseriate, gray.

Murdannia yunnanensis is similar to M. wightii R. S. Rao & Kammathy (described from India), but differs in having pedicels mostly straight in fruit, filaments of fertile stamens sparsely red torulose villous, and capsules smaller.

* Swamps in forests, forest margins; ca. 800 m. S Yunnan (Xishuangbanna Dai Zu Zizhizhou).