Description from Flora of China
Rhizophora caseolaris Linnaeus, Herb. Amboin. 13. 1754; Sonneratia acida Linnaeus f.; S. evenia Blume; S. neglecta Blume; S. obovata Blume; S. ovalis Korthals.
Trees, columnar, 5-20 m tall. Pneumatophores ca. 1 m, thin, pointed; ultimate branchlets pendulous, 4-angled. Petiole 2-9 mm; leaf blade elliptic to broadly elliptic or broadly oblong, 4-11 × 2-7 cm, midrib prominent with inconspicuous lateral veins, base rounded, narrowly to broadly attenuate on petiole, apex rounded with minute, thick mucro. Flowers 5-7-merous. Floral tube 2.5-3 cm at anthesis, smooth, flattened in mature fruit; sepals adaxially green, often red-streaked, 1.4-1.9 cm. Petals red, linear, 1.8-2.9 cm × 1-3 mm. Staminal filaments red, sometimes white distally. Fruit [2-]4-5 cm in diam., broader than floral tube. Seeds irregularly angular, ca. 7 mm. Fl. winter, fr. spring-summer. 2n = 22, 24.
Coastal mangrove communities, tidal creeks, in muddy soil. Hainan [Cambodia, India, Indonesia, Malaysia, N New Guinea, Sri Lanka, Thailand, Vietnam; N Australia, Pacific islands].