Description from Flora of China
Viola enneasperma Linnaeus, Sp. Pl. 2: 937. 1753; Hy banthus suffruticosus (Linnaeus) Baillon; Ionidium enneaspermum (Linnaeus) Ventenat; I. suffruticosum (Linnaeus) Gingins; V. suffruticosa Linnaeus.
Subshrubs, with a long, slender tap root. Stems numerous, procumbent, usually 10-20 cm tall, rarely to 40 cm. Young branches canaliculate, ± puberulous. Leaves alternate, sessile or subsessile; stipules greenish, triangular or subulate, very small, ciliate; leaf blade linear-lanceolate, linear-oblanceolate, or narrowly spatulate, unequal in size, 0.5-3.5 × 0.2-0.5 cm, midvein slightly raised abaxially, lateral veins inconspicuous, base cuneate, decurrent, margin entire, sparsely 1-3-serrulate, apex acute, rarely acuminate, mucronulate. Flowers solitary in leaf axils, blue-purple; pedicels not exceeding leaves, 2-bracteolate near flower; bracteoles opposite, lanceolate or subtriangular, membranous, ciliate. Sepals subequal, lanceolate, 2-3 mm, margin membranous, white, ciliate. Petals irregular, upper 2 smallest, oblong, apex acute, lateral 2 ovate-orbicular, apex slightly recurved, lower 1 largest, 6-7 mm, ca. 2 × as large as others, anterior half broadest, 2 lateral sides incurved, more deeply colored, shortly spurred. Stamens free; filaments short, 2 with curved calcarlike (spurlike) appendages; anthers longitudinally dehiscent, appendages at top of connectives yellow-brown, membranous. Ovary subglobose; styles clavate, base dilated, slightly curved in upper narrow part; stigmas slightly incurved. Capsule pendulous, globose. Seeds creamy-yellow, ovoid-orbicular, conspicuously longitudinally striate. Fl. Jun-Jul, fr. Jul-Aug. 2n = 16*.
Thickets along river banks, open grasslands, sandy places near seashores; below 500 m. S Guangdong, Hainan, S Taiwan [tropical Africa, tropical Asia, Australia].