1. Hydnocarpus annamensis (Gagnepain) Lescot & Sleumer, Fl. Cambodge Laos Vietnam. 11: 10. 1970.
大叶龙角 da ye long jiao
Taraktogenos annamensis Gagnepain in Lecomte, Fl. Indo-Chine, Suppl. 1: 206. 1939; Hydnocarpus merrillianus H. L. Li (1943), not Sleumer (1938); T. merrilliana C. Y. Wu.
Trees, evergreen, 8-25 m tall; bark gray-brown; branchlets terete, gray-brown or reddish tomentose; winter buds ovoid-globose, scales brown tomentose outside. Petiole 1-2.5 cm, brown tomentose; leaf blade green abaxially, deep green adaxially, obovate, elliptic-oblong, or oblong-lanceolate, 17-35 × 7-12 cm, thinly leathery, abaxially sparsely hairy or hairy only along veins, adaxially shiny and glabrous, midvein raised on both sides, lateral veins 5-10 pairs, reticulate veins conspicuous, base broadly acute, cuneate, asymmetric, margin entire, apex obtuse, contracting abruptly to a short acumen. Inflorescence axillary; flowers solitary, or 2 or 3 together in cymes 1-2 cm; rachis pubescent. Pedicels 3-5 mm, together with peduncles densely brown tomentose. Staminate flowers deep green; sepals 4 or 5, orbicular, 5-6 mm, outside yellowish tomentose, inside glabrous; petals 4 or 5, suborbicular, outer petals 4-5 mm, inner ones smaller, both sides (excl. scale) glabrous, margin ± fimbriate; scale 3-3.5 mm, apex hairy and fimbriate; stamens many (ca. 25); filaments 4-5 mm, hairy; anthers globose or subcordate, apex ± acute; pistillode absent. Pistillate flowers greenish, ca. 1.5 cm in diam.; sepals 4, oblong, 6-7 mm, outside densely rusty tomentose, inside glabrous, margin ciliate; petals 8, suborbicular, inner ones smaller, outer ones larger, both sides (excl. scale) glabrous, margin ± fimbriate; scales as for staminate flowers; staminodes 8; ovary ovoid-orbicular, slightly 8-angled, densely pubescent, styles nearly absent, stigmas 4 or 5. Berry subglobose, 4-6 cm in diam., reddish or brownish tomentose interspersed with longer stiffer bristles, stigmas persistent, pericarp cross-section with radially striate layer. Seeds numerous. Fl. Apr-May, fr. Jan-Dec.
Moist mountain slopes, thickets along streams; 200-600 m. S Guangxi, S Yunnan [Vietnam].
Li and Feng (in Fu & Jin, China Pl. Red Data Book 1: 308-309. 1992, as Taraktogenos annamensis) gave the conservation status of this species as rare, i.e., not in imminent danger of extinction but with very limited or scattered distribution. The 2006 IUCN Red List of Threatened Species (www.iucnredlist.org, at 19 January 2007, as T. annamensis ) gave the status as vulnerable (VU A1cd). In China the species has suffered catastrophic damage due to clearance for agriculture, and the fruits are often harvested for their medicinal value.
Treatments disagree with respect to petal number in the male flower. Wu (Acta Phytotax. Sin. 6: 226. 1957) recorded 4 or 5 petals, which agrees with material seen for the present treatment. Lescot (Fl. Cambodge Laos Vietnam 11: 10. 1970) recorded (7 or)8 petals.