Pl. Vasc. Gen. 1: 70; 2: 50. 1837.
Shrubs, armed with thorns, secondary branches and branchlets green; bud scales absent. Leaves early deciduous, usually absent by flowering, opposite or subopposite; blade not gland-dotted; pinnately veined (obscurely, appearing 1-veined or vaguely 3-veined from base). Inflorescences axillary, cymes or flowers solitary; peduncles and pedicels not fleshy in fruit. Pedicels present. Flowers bisexual; hypanthium broadly obconic to hemispheric-campanulate, 1.5–3 mm wide; sepals (4–)5, spreading, whitish to greenish white, ovate-triangular or triangular-deltate, keeled adaxially; petals (4–)5, white, sometimes yellow-tipped, hooded, spatulate, clawed; nectary fleshy, 5-angled, lining hypanthium; stamens (4–)5; ovary superior, 3-locular; style 1. Fruits capsules.
sw United States, Mexico.
Species 2 (2 in the flora).
|1||Secondary branches and branchlets glabrous or glabrate, branchlets 1–1.5 mm diam.; leaf blades elliptic-oblong to obovate, 1- or vaguely 3-veined from base; hypanthia broadly obconic, 2.5–3 mm wide, sides nearly straight; sepals triangular-deltate, length equaling width, margins straight; petals 2–2.5 mm, deeply hooded.||Adolphia californica|
|1||Secondary branches and branchlets minutely and persistently short-hispid, slowly glabrescent, branchlets usually 0.5–1 mm diam.; leaf blades narrowly oblanceolate to linear, 1-veined from base; hypanthia hemispheric-campanulate, 1.5 mm wide, sides convex; sepals ovate-triangular, length nearly 2 times width, margins curved; petals 1.2–1.5 mm, shallowly hooded.||Adolphia infesta|