响盒子 xiang he zi

Trees up to 40 m tall in wild; stem and main branches densely spiny; indumentum yellowish brown; branches densely lenticellate, glabrous. Stipules lanceolate or ovate-lanceolate, 10-15 × 2-3 mm, pubescent, caducous; petiole 4-20 cm, apex with 2 glands; leaf blade broadly ovate, 5-29 × 5-17 cm, papery, abaxially pilose along midrib, adaxially glabrous, base cordate, margins ± shallowly dentate-serrate, apex caudate-acuminate, mucronulate; midrib elevated on both surfaces, lateral veins 10-13(-16) on each side. Male flowers: inflorescence ovoid-conical, (1.6-)4-5 × (0.8-)1.5-2 cm, mostly dark red; peduncles (1.2-)7-10 cm, often with solitary female flower at base; pedicel ca. 2 mm; calyx tube 2-3 mm; stamen connectives and filaments connate into column, 4-12 mm, longest at base of catkin; anthers in (1 or)2 or 3 whorls. Female flowers: pedicel 10-17 mm, after anthesis up to 6 cm; calyx tube truncate, 4-6(-8) mm, enclosing ovary; style column 2-5 cm; stigmatic disk dark purple, 1.5-2.5 cm in diam., with 11-14 obtuse lobes, spreading radially. Fruiting pedicel pendent, to 6 cm; fruit oblate, 3-5 × 8-9 cm in diam., becoming reddish brown, concave at apex and base, longitudinally grooved. Seed ca. 2 cm in diam. Fl. May, fr. Aug.

Cultivated. Hainan, Hong Kong [native to tropical America, widely grown elsewhere].

This species is cultivated for medicine and as an ornamental. The latex is extremely toxic. The distinctive fruit was once used for holding fine dry sand used for blotting ink before the introduction of blotting paper, hence the common name "sand box tree." The distinctive dolphin-shaped mericarps are sometimes used in necklaces.