Arbutus occidentalis McVaugh & Rosatti var. villosa McVaugh & Rosatti, Contr. Univ. Michigan Herb. 11: 304. 1978. Type: Mexico. Mexico: Distr. Temascaltepec, between Cumbre and Cimientos, 26 Jan 1936 (fl), Hinton et al. 8847 (holotype: MICH; isotypes: C, GH, K, LAM, NY, US).Shrub, prostrate and spreading or upright, 0.3-1.5(-2) m tall, from a burl-like base or rootstock; bark on larger twigs brownish-red, smooth or slightly roughened, exfoliating in small flakes to the base of the canes. Leaves pale or dark green or glaucous-green, sometimes with a blush of red or copper color, especially along the margins, elliptic or slightly ovate-elliptic, 4-7.5(-9) x 1.5-3.5(-4.2) cm, basally tapered or rounded, rarely subtruncate, apically acute, the margins flat or very slightly revolute, smooth or toothed, varying on the same shoot, upper surface glossy, rugulose, glabrous or with some pubescence along the midvein toward base of blade, lower surface glabrous or pubescent, sometimes densely so, the hairs tan or brown; petiole 0.4-1.5 cm long, 1/9(aver. 1/6)1/3 the length of the blade, pubescent or glabrous, usually some of the hairs gland-tipped but not conspicuously so, the gland-tipped hairs scarcely longer than the non-glandular ones. Inflorescence a terminal simple raceme or a cluster of racemes, the branches few, axes including pedicels sparsely to densely pubescent, sometimes whitened woolly, with scattered or abundant glandular hairs intermixed with non-glandular ones. Flowers at first erect then nodding slightly on curved, accrescent pedicels, subtended at the base by a clasping, reddish, accrescent bract to 5.1 mm long, often almost as long as, or slightly exceeding the pedicel length (exceptional material with much elongated pedicels), more or less enclosing one or two smaller bracteoles; calyx at first cupulate, becoming reflexed in age, lobes ca. 2.7(-3.2) mm long, obtuse, ciliolate, glabrous or sparsely pubescent, pale reddish or tan; corolla 4.8-5.4 mm long, pale pink to red, drying to reddish-brown, ventrally sometimes pubescent in lines; filaments ca. 2.2 mm long including the swollen base, glabrous above, silky pubescent below, spurs 1/2-3/4 the length of the thecae, the latter ca. 1.5 mm long; ovary glabrous or pubescent, ovules several per locule. Fruit up to 8 mm diam. when ripe, bright orange-red; seeds, ca. 2.4 mm long, 1 or 2(-3) developing in each locule.
Distribution. Rocky cliffs and ledges and open pine woodlands or parklands in the mountains of Mexico from about 26°50'N, 108°5'W in NE Sinaloa thence patchily southward and eastward to SE Oaxaca; 2100-3660 m, most collections from 2300-3350 m; flowering January to June, peaking in late February or early March, more or less throughout the range, rarely flowering desultorily in October or November; fruit appearing in July, ripening usually in October.