Description from Flora of China
Portulaca hainanensis Chun & How.
Herbs perennial, 5-10 cm. Roots fleshy, 4-8 mm thick. Stems not articulated, diffuse, branched basally, 1-1.5 mm thick; leaf axils villous. Leaves alternate; petiole short; leaf blade flat, obovate or linear-spatulate, 5-10 × 2-4 mm, base attenuate, apex obtuse. Flowers solitary, surrounded by involucre of 4-6 bracts. Sepals ovate-deltate, ca. 2.5 mm, veined. Petals 5, yellow or yellowish, elliptic, ca. 2.5 mm. Stamens 25-30. Ovary ovoid. Stigma 5-lobed. Capsule glossy straw colored apically, broadly ovate, compressed, 2.5-4 × 2.5-3 mm. Seeds black, turning iridescent gray when fully mature, orbicular-reniform, ca. 0.7 mm; testa cells interlocking, slightly raised. Fl. and fr. summer.
* Seashores, coral sands, on rocks. Guangdong (Dongsha Dao), Hainan (Yaxian), Taiwan.