3. Amygdalus triloba (Lindley) Ricker, Proc. Biol. Soc. Wash. 30: 18. 1917.
榆叶梅 yu ye mei
Prunus triloba Lindley, Gard. Chron. 1857: 268. 1857; Amygdalus triloba var. plena (Dippel) S. Q. Nie; A. triloba var. truncata (Komarov) S. Q. Nie; Cerasus triloba A. I. Baranov & Liou; C. triloba var. plena (Dippel) A. I. Baranov & Liou; C. triloba var. truncata (Komarov) A. I. Baranov & Liou; Prunus triloba var. plena Dippel; P. triloba var. truncata Komarov.
Shrubs, rarely trees, 2–3 m tall. Branches spreading, much branched; current year’s branchlets gray to grayish black; previous year’s branchlets grayish brown, glabrous or slightly pubescent when young, glabrescent. Winter buds brown, 2–3 mm, apex acute; scale margins pubescent. Leaves on short branchlets often fasciculate, those on previous year’s branches alternate; petiole 5–10 mm, pubescent; leaf blade broadly elliptic to obovate, 2–6 × 1.5–3(–4) cm, abaxially pubescent, adaxially pilose or glabrous, base broadly cuneate, margin coarsely serrate or biserrate, apex shortly acuminate and usually 3-lobed. Flowers 1 or 2, opening before leaves, 2–3 cm in diam. Pedicel 4–8 mm, 5–10 mm in fruit, glabrous or initially puberulous. Hypanthium broadly campanulate, 3–5 mm, outside glabrous or puberulous. Sepals ovate to ovate-lanceolate, nearly as long as hypanthium, outside glabrous or puberulous, margin sparsely minutely serrate near apex. Petals pink, suborbicular to broadly obovate, 6–10 mm, apex obtuse to emarginate. Stamens 25–30, shorter than petals. Ovary densely pubescent. Style somewhat longer than stamens. Drupe subglobose, 1–1.8 cm in diam., pubescent, apex mucronulate; mesocarp thin, splitting when ripe; endocarp subglobose, ± uncompressed on both sides, 1–1.6 cm in diam., surface irregularly reticulate, apex obtuse. Fl. Apr–May, fr. May–Jul.
Forests, thickets; 600--2500 m. Anhui, Gansu, Hebei, Henan, Heilongjiang, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Shaanxi, Shandong, Shanxi, Zhejiang [Korea, Russia].
Single- and double-flowered cultivars are cultivated as garden ornamentals.