Dipentodon sinicus
Credits
Article from New Trees by John Grimshaw & Ross Bayton
Recommended citation
'Dipentodon sinicus' from the website Trees and Shrubs Online (treesandshrubsonline.
Genus
Other taxa in genus
Tree to 10 m. Bark pale, warty and with large corky lenticels. Leaves lanceolate to broadly ovate-oblong, 7–15(–20) 2–9 cm, glossy green above, more or less glabrous except for a few hairs on the veins below, apex acuminate, margins finely dentate, lateral veins looping just inside the margin (camptodromous); petiole 0.7–1 cm, subtended by two caducous stipules 1 cm long. Inflorescence an axillary umbellate cyme to 2.5 cm diameter, subtended by 5–12 caducous bracts 4–5 1.5–3 mm, forming an involucre when inflorescence is young, but falling before the flowers open; flowers numerous, up to 100 or more, white, with 10 (–14) perianth segments of c.1 mm long in two whorls borne on a cup-shaped disc, stamens inserted on the disc opposite the outer whorl of perianth segments, exceeding the segments in length; style 2–3 mm, ovary pubescent. Fruit a strangely shaped capsule curving from the thin proximal end to a swollen distal portion, splitting along three sutures to reveal the seed, illustrated here for the first time by Hazel Wilks (Figure 32). Flowering May to September, fruiting August to October (China). Dunn 1911, Merrill 1941, Jinshuang & Bartholomew 2007. Distribution CHINA: Guizhou, Guangxi, southeastern Xixang, Yunnan; INDIA; MYANMAR. Habitat Montane broadleaved evergreen forests, especially in open places by rivers or trails, between 900 and 3200 m asl. USDA Hardiness Zone 8–9. Conservation status Lower Risk. Illustration Merrill 1941; NT312, NT313.
Dipentodon sinicus was first found by Augustine Henry near Mengtze, Yunnan in 1898, and was immediately recognised as something curious. The name is derived from the odd floral morphology in which the calyx lobes and petals are identical and inserted, as if in one whorl, looking like a 10-lobed perianth (hence dipentodon, meaning ‘twice-five teeth’). It has a wide distribution and is not uncommon in western China and Myanmar, so its scarcity in cultivation is strange. It is grown at the San Francisco Botanical Garden, and was collected in 1997 by the Gaoligongshan Expedition of the Royal Botanic Garden Edinburgh (GSE 97), but the only specimen seen in research for the current work is at Tregrehan. This is a slender tree of about 5 m, with spreading branches and glossy dark green leaves that turn crimson in autumn (T. Hudson, pers. comm. 2005). The inflorescences are borne all along the shoots, attractively held above the foliage, and the fruits remain in the same position. Material is so limited that it is difficult to make any comments on the requirements of this species in cultivation, but it should be tried in a warm and possibly moist situation.
