Description from Flora of China
Commelina simplex Vahl, Enum. Pl. 2: 177. 1805; Aneilema sinicum Ker Gawler.
Herbs perennial. Roots fibrous, robust, 2--3 mm in diam., densely lanate. Rhizomes absent. Main stem undeveloped, short, with basal, rosulate leaves; fertile stems 2--4 arising from base of main stems, usually erect, sometimes ascending, to 50 cm. Basal leaves with sheath hirsute only on 1 side; blade linear, 15--35 × 0.6--1.5 cm, glabrous. Cauline leaves often 2 or 3, rarely more; proximal leaf blades to 12 cm, distal ones shorter, sometimes only ca. 10 mm, glabrous. Cincinni several, to 2 cm, forming narrow panicles ca. 5 cm; peduncle ca. 10 mm; involucral bracts ovate or ovate-lanceolate, less than 10 mm, membranous, caducous; bracts subequaling sepals, caducous; flowers pendulous in bud, ascending at anthesis; pedicels straight, ca. 5 mm in fruit. Sepals elliptic, 4--5 mm. Petals purple, obovate-orbicular. Fertile stamens 2; filaments bearded; staminodes 3; antherodes 3-sect. Capsule ovoid-globose, trigonous, 4--5 mm. Seeds 2 per valve, brown-black, white radiate verrucose. Fl. Apr--Sep.
Forests, marshes, humid grasslands; near sea level to 2700 m. Guangdong, Guangxi, SW Guizhou, S Hainan (Sanya), C and SW Sichuan, S and W Yunnan [India, Indonesia, Laos, Malaysia, Myanmar, Thailand, Vietnam; E Africa].