Description from Flora of China
Hibiscus populneus Linnaeus, Sp. Pl. 2: 694. 1753; Bupariti populnea (Linnaeus) Rothmaler; H. populneoides Roxburgh; Malvaviscus populneus (Linnaeus) Gaertner; Parita populnea (Linnaeus) Scopoli; Thespesia howii S. Y. Hu; T. populneoides (Roxburgh) Kosteletzky.
Trees or shrubs, evergreen, 3-6 m tall. Branchlets with minute brown peltate scales, sometimes dense. Stipules filiform-lanceolate, 2-7 mm, usually caducous; petiole 4-10 cm, scaly; leaf blade ovate-cordate to triangular, 7-18 × 4.5-12 cm, abaxially with scales, adaxially glabrous or with scales, base truncate to cordate, margin entire, apex long caudate. Flowers solitary, axillary. Pedicel 2.5-6 cm, densely scaly. Epicalyx lobes 3-4, filiform-lanceolate, 8-10 mm, usually caducous, scaly. Calyx cup-shaped, 1-1.5 cm in diam., subtruncate with 5 ca. 0.5 mm teeth, densely scaly. Corolla yellow, adaxially purple at base, campanulate, ca. 5 cm. Staminal column ca. 25 mm. Fruit stipe 6-8 cm. Capsule globose to pyriform, ca. 5 × 2 cm in diam., slightly fleshy, ± indehiscent. Seeds triangular-ovoid, 8-9 mm, brown hairy or glabrous, veined. Fl. year-round.
The wide distribution of this species is due to the capacity of its fruits to float in seawater and stay alive for months. It is often cultivated as a shade tree.
Sea coasts, open situations; near sea level. Guangdong, Hainan, Taiwan [Cambodia, India, Japan (Okinawa, Ryukyu Islands), Philippines, Sri Lanka, Thailand, Vietnam; Africa; widely distributed in the tropics].