Sylva Tell., 42. 1838.
Shrubs. Branchlets 4-angled, with corky ridges. Leaves persistent, opposite; stipules present; petiole present or absent; blade margins finely toothed; venation pinnate. Inflorescences axillary, cymes or flowers solitary. Flowers bisexual, radially symmetric; perianth and androecium perigynous; hypanthium free from ovary; sepals 4, distinct; petals 4, reddish brown to yellowish green; nectary intrastaminal, lining hypanthium, fleshy; stamens 4, adnate to nectary margin; staminodes 0; pistil 2-carpellate; ovary superior, immersed in and adnate to nectary, 2-locular, placentation axile; style 1; stigmas 2; ovules 2 per locule. Fruits capsules, 2-locular, ellipsoid or obovoid, apex not beaked. Seeds 1 per locule, ellipsoid or obovoid, not winged; aril yellow or white, surrounding base and 1 side of seed, lacerate or fringed. x = 16.
North America, n Mexico.
Species 2 (2 in the flora).
Pachystima and Pachistima are orthographic variants used frequently in the flora area.