Trees 7–13 m tall. Branchlets red-brown, glabrous. Leaves 7–10 × 2.5–3.5 cm, elliptic-lanceolate, oblong, or oblong-elliptic, both sides of leaves glabrous, 6–9 pairs of secondary veins on each side of midrib, margin serrulate, apex acuminate; petiole 6–10 mm. Inflorescences racemes or panicles 3.5–4 cm long, 9–16-flowered, calyx densely stellate-pubescent, corolla lobes elliptic to elliptic-oblong, c. 1.4 × 0.5 mm. Fruit dry drupe, red-brown cylindrical, terete, 7.5–11 × 2.5–6 cm, with small brown small spots, 6–8-ribbed, smooth between ribs (Hwang & Grimes 1996).
Distribution China Yunnan Vietnam Northern
Habitat Mixed Forests
USDA Hardiness Zone 8a-8b
RHS Hardiness Rating H4
Conservation status Not evaluated (NE)
Rehderodendron indochinense is another poorly understood and rarely cultivated species. The BGCI plant search facility only list two ex-situ sites cultivating this species in 2018, though it is likely that it is more widely cultivated than this suggests. Recent introductions from Vietnam under the name R. indochinense are in the UK horticultural trade and young plants are cultivated sucessfully at Caerhays in southwest England, where they exhibit a fairly fast growth rate. Several introductions have been made from northern Vietnam by Crûg Farm Plants under Wharton & Wynn-Jones (WWJ) or Bleddyn & Sue Wynn-Jones (BSWJ) numbers. Field notes available on their website indicate a certain variability in tree size between populations, but the species always seems to be recognisable by its spotted fruits. Bleddyn Wynn-Jones (Crûg Farm Plants website 2019) notes that BSWJ 11805 has been ‘unflinchingly hardy’ in North Wales.
The 2014 joint Hanoi, UBC, Longwood and RBGs Edinburgh and Kew expedition to Vietnam (HNE) collected seed from a number of different Rehderodendron and believe they collected this species but must await flowering and fruiting material before confirming the identifcation (R. Baines pers. comm. 2018). The David C. Lam Asian Garden, part of UBC Botanical Garden in Vancouver, was cultivating R. indochinense at least as early as 2008, but by 2018 it was no longer listed as growing in that collection.