5. Chaenomeles thibetica T. T. Yu, Acta Phytotax. Sin. 8: 234. 1963.
西藏木瓜 xi zang mu gua
Shrubs or small trees, 1.5–3 m tall; usually with many thorns. Branchlets red or purplish brown when young, blackish brown when old, terete, with sparse, oblong lenticels; buds reddish brown, triangular, with few scales, apex obtuse. Stipules subfalcate or subreniform, large, ca. 1 × 1.2 cm, herbaceous, margin irregularly serrate, apex acute, rarely obtuse; petiole short, 1–1.6 cm, initially brown tomentose, soon glabrous; leaf blade dark green adaxially, ovate-lanceolate or oblong-lanceolate, 6–8.5 × 1.8–3.5 cm, leathery, midvein and lateral veins conspicuous abaxially and impressed adaxially, abaxially densely brown tomentose, base cuneate, margin entire, apex acute. Pedicel short. Flowers 3- or 4-fascicled. Hypanthium campanulate, abaxially glabrous. Sepals reflexed, triangular, ca. 2 mm, glabrous. Petals and stamens not seen. Styles 5, connate and densely gray pubescent at base. Pome fragrant, yellow, oblong or pear-shaped, 5–9 cm in diam., sepals caducous; fruiting pedicel short. Fl. Jul, fr. Sep–Oct.
Among shrubs on slopes or in valleys; 2600--3800 m. W Sichuan, E Xizang.
Yu and Lu (in FRPS 36: 354. 1974) suggested that this species is a hybrid between Chaenomeles cathayensis and Docynia delavayi.