A shrub to c. 4 m tall, rarely arborescent. Shoots glabrous to densely hairy; older bark grey-brown, exfoliating in long strips. Leaves ovate to lanceolate, 4–13.5 × 2.6–5.7 cm, the base rounded to cuneate and the tip abruptly acuminate; pubescence variable; margin entire; petiole 6–14 mm. Flowers May–June; inflorescence often paired at branch-tips; peduncle to 1 cm long, with 2 lanceolate bracts midway. Ovary with kidney-shaped bracts. Calyx only fused at the base, with linear lobes 4–6 mm long; corolla dark purple to white, the throat marked with orange, 2.2–2.6 cm long, deely saccate at the base. Style as long as the corolla tube and sparsely hairy. Fruit July-November, enclosed between the 2 large wings of the episepals which are 1.3–2 cm wide and kidney-shaped (attached at the side). (Landrein & Farjon 2020).
Distribution China Gansu, Sichuan, Yunnan
Habitat Mixed forests and scrub, 900–3000 m.
USDA Hardiness Zone 5
RHS Hardiness Rating H5
Conservation status Least concern (LC)
Taxonomic note As Dipelta ventricosa is not recognised by some authorities, including Christenhusz (Christenhusz 2013), the combination in Linnaea has not been published.
This taxon differs from Dipelta yunnanensis in the more swollen belly at the base of the corolla and in its rather narrower leaves with long, abrupt points, but many intermediate forms occur where the two plants grow together (Landrein & Farjon 2020); it is customary for growers in the UK and Ireland to treat it as a good species while in the United States it is either universally treated as synonymous with D. yunnanensis, or is not grown. In 1904 Ernest Wilson sent roots from Washan in Sichuan to Veitch’s Coombe Wood nursery in England (Bean 1976; Hemsley 1908) and D. ventricosa remains available from about as many UK nurseries as the other Dipelta species (Royal Horticultural Society 2020), despite being ‘notoriously difficult to propagate’ (Bluebell Arboretum and Nursery 2021). It thrives as far north as Crathes Castle on Deeside (Dirr 2009). The flowers, seen in detail, are perhaps the most brilliantly coloured in the genus.