Heliotropium marifolium Retz.

Subshrubs 10-15 cm tall, much branched; branches spreading or prostrate, sparsely hirtellous. Leaves crowded, ± opposite when young, alternate in age, ± sessile, narrowly oblong to lanceolate, 0.8-1.5 cm × 2-3 mm, densely antrorse appressed hirtellous, base cuneate, apex acute. Cymes terminal, scorpioid, 1-2.5 cm; bracts spreading, lanceolate, 3-4 mm. Flowers sessile, crowded. Calyx 2.5-4 mm, densely hispid outside, glabrous below middle inside; lobes lanceolate to ovate-lanceolate, slightly enlarged in fruit. Corolla white, tubular, 2-3 mm, base ca. 1 mm wide; throat constricted to 0.5 mm; limb ca. 1 mm wide, densely hispid outside, slightly exceeding calyx or not; lobes ovate, ca. 0.5 mm. Filaments extremely short, inserted near base of corolla tube; anthers ovate-lanceolate, ca. 0.5 mm, apices thickened, coherent. Ovary globose. Style less than 0.5 mm; stigma ringlike at base, conical at apex. Fruit globose, ca. 2 mm in diam., densely pale yellow hirtellous, divided at maturity into 4 1-seeded mericarps; mericarps ca. 1.5 mm, white spotted adaxially near middle. Fl. Jun.

Arid, sandy beaches. Hainan [Cambodia, India, Indonesia, Malaysia, Pakistan, Sri Lanka, Thailand, Vietnam].

Vòi voi chụm (danh pháp: Heliotropium marifolium) là loài thực vật có hoa trong họ Mồ hôi. Loài này được J.König ex Retz. miêu tả khoa học đầu tiên năm 1781.

大苞天芥菜（学名：Heliotropium marifolium）为紫草科天芥菜属的植物。分布于马来西亚、印度尼西亚、斯里兰卡、越南以及中国大陆的海南等地，多生长于干旱无荫的海边沙地，目前已由人工引种栽培。