Comarostaphylis polifolia (Kunth) Zucc. ex Klotzsch

Description

Description: Erect to spreading or sprawling, often gnarled, evergreen shrubs to small trees, 0.2-4(-6) m tall, capable of stump-sprouting; bark peeling or flaking in small pieces or exfoliating in irregular plates, gray to reddish-brown; young twigs glabrous to tomentose to densely glandular hirsute, trichomes stalked, swollen-headed and glandular, or hyaline and eglandular. Leaves coriaceous, linear to elliptic, oblanceolate or oblong, plane or strongly revolute, 2-7.6 x 0.3-1.9 cm, basally tapering to cuneate or rounded, apically obtuse to acute, marginally entire or rarely with serrations, upper surface glabrous or with slight pubescence, lower surface glabrous to tomentulose to tomentose, sometimes densely so, pubescence sometimes ferruginous, glandular trichomes sometimes also present, especially along the midrib; petioles 2-7.5 mm long, with pubescence as on young twigs. Inflorescences racemose, sometimes slustered, at times paniculate, 2.2-11 cm long; rachis, pedicels, floral bracts, bracteoles and calyx puberulent, tomentulose, lightly canescent or glandular hirsute, trichomes glandular or eglandular; floral bracts broadly lanceolate to ovate, navicular or carinate, acute to acuminate, 1.4-7.4 x to 2.6 mm, ciliate or not; pedicels 3-11(-21) mm long; bracteoles basal to subdistal, 1.6-2.9 mm long, ciliate or not. Flowers: calyx lobes narrowly triangular or ovate-triangular, 1.1-3.1 x 0.9-2.3 mm, acute to acuminate, ciliate or not; corollas 4.9-8.2 x 3-6 mm, glabrous or with slight pubescence, white to pink, the lobes 0.9-1.7 x 1.1-2.2 mm wide; stamens 2-3.7 mm long; filaments 1.6-3.3 mm long, villous; anthers 1-1.5 x 0.6-1 mm, the spurs 0.4-0.9 mm long; ovary glabrous or with eglandular trichomes, sometimes densely villous; style 2.8-5.4 mm long, glabrous or with eglandular trichomes. Fruit red when immature, dark purple to black at maturity, 4-9 mm in diam.; seeds 1.6-3 x 1.1-1.4 mm, surface reticulate.

Distribution: Endemic to Mexico, from Oaxaca north and west to Coahuila and Chihuahua, in "Matorral Xerofilo" (Rzedowski, 1978), or in dry pine or oak-pine forests, at elevations of 1500-2800(-2950) m. Flowering and fruiting throughout the year but most commonly Apr-Sep and Jul-Nov, respectively.

Type: Mexico, Guanajuato: Near Villalpando, 2433 m, Humboldt & Bonpland s.n. (holotype, P, n.v.; isotypes, L-fragments, P, photo, Diggs neg. 23).

Key to Subspecies of Comarostaphylis polifolia: 1. Inflorescences and often young branches and petioles with glandular trichomes; leaves usually revolute or folded; widespread.     2. Leaves usually strongly revolute; ovary pubescent; twigs and petioles usually glandular hirsute; shrubs to 4(-6) m tall; widespread ............. subsp. polifolia     2. Leaves usually not revolute, often conduplicately folded at maturity; ovary glabrous; twigs and petioles usually without glandular trichomes; shrubs to 2 m tall; Coahuila ............... subsp. coahuilensis 1. Inflorescences and young branches and petioles without glandular trichomes; leaves usually plane; Nuevo León, Tamaulipas, and San Luis Potosí ............... subsp. minor