Description from Flora of China
Aneilema keisak Hasskarl, Commelin. Ind. 32. 1870; A. coreanum H. Léveillé & Vaniot; A. oliganthum Franchet; A. taquetii H. Léveillé.
Herbs perennial. Roots fibrous. Rhizomes horizontal, elongate. Stems creeping proximally, ascending distally, branched, to 40 cm; internodes ca. 8 cm, with a line of dense, white hairs. Leaves sessile; leaf sheath with a line of hairs on 1 side; leaf blade spreading or slightly folded, linear-lanceolate or linear-elliptic, 2--8 cm × 5--8 mm, ciliate only in proximal part, apex acuminate. Cincinni terminal and axillary, usually 1-flowered; peduncle 1--4 cm (terminal ones longer), with linear bract at middle, sometimes with a flower in axil of bract; pedicels 1--2 cm. Sepals narrowly oblong, 6--10 mm. Petals pink, purple-red, blue-purple, or pale blue, obovate. Fertile stamens 3; filaments densely bearded; staminodes 3; antherodes sagittate. Capsule narrowly ovoid, trigonous, 5--10 × 2--3 mm, acute to subacuminate at both ends. Seeds 4 (sometimes fewer) per valve, uniseriate, gray, slightly flattened. Fl. Aug--Sep.
Murdannia keisak is perhaps not distinct from M. triquetra. This complex is widely distributed from India to Japan (and recently recorded in E North America). The two taxa are extremely similar in habit and other qualitative characters, but size of sepals, shape and size of capsule, and number and shape of seeds show differences correlated with geographic distribution.
Wet places. S Fujian (Xiamen Shi), N Jiangxi (Jiujiang Shi, Xinjian Xian), E Jilin (Chunhua), Liaoning, NE Zhejiang (Zhenhai Xian) [S Japan, Korea].