5. Leptopus fangdingianus (P. T. Li) Vorontsova & Petra Hoffmann, Kew Bull. (in press).
方鼎木 fang ding mu
Archileptopus fangdingianus P. T. Li, J. S. China Agric. Univ. 12(3): [see Kew Bull. for page number]. 1991.
Erect shrubs, 1-2 m tall, monoecious. Branchlets terete, green-brown. Stipules triangular, base not auriculate, apex acute, ferruginous to almost black; petiole 4-8 × 0.7-0.9 mm; leaf blade elliptic, (3-)6-10(-12) × (2-)2.5-4(-4.5) cm, thickly papery, drying slightly discolorous yellowish green, both surfaces glabrous to sparsely hirsute, base acute, apex acute to acuminate; secondary veins 4 or 5 pairs. Inflorescences unisexual, always fasciculate. Male flowers 1 or 2 per fascicle, 2.5-3 mm in diam.; pedicel 4-5 mm; sepals obovate to oblong, 1-1.8 × 0.7-0.9 mm, apex rounded, eglandular; petals obovate to linear, 0.5-0.7 × 0.15-0.3 mm, apex acute to rounded; disk bilobed for ca. 4/5 of length. Female flowers 1 or 2 per fascicle, ca. 4.5 mm in diam., rotate; pedicel 20-25 mm; sepals oblong to elliptic, 2-3.5 × 1-1.5 mm, apex acute, eglandular; petals linear, 0.5-0.8 × ca. 0.1 mm, apex rounded; disk bilobed for 3/4 of length; ovary 4-6-locular, glabrous; styles 4 or 6, glabrous. Fruiting pedicel 17-25 mm; sepals not accrescent; capsule smooth to faintly reticulate, glabrous, drying brown. Seed smooth, brown.
● Evergreen forest understories on limestone. Guangxi.
This narrow endemic was originally described as the unispecific genus Archileptopus P. T. Li (loc. cit.), based on its extrorse anthers and 4 or 5 ovary locules, as distinct from the introrse anthers and 3 locules of Leptopus. However, the anthers were found to be anatomically identical to those of Leptopus species in bud. Increased locule number can be observed in L. hainanensis and L. pachyphyllus as well as in Archileptopus. Molecular phylogenetic analysis of tribe Poranthereae using ITS and matK sequences places Archileptopus within Leptopus with high bootstrap support (Vorontsova et al., Amer. J. Bot. 94: 2026-2040. 2007). Archileptopus is affiliated with L. clarkei.