Monographs Details:
Authority:

Luteyn, James L., et al. 1995. Ericaceae, Part II. The Superior-Ovaried Genera (Monotropoideae, Pyroloideae, Rhododendroideae, and Vaccinioideae P.P.). Fl. Neotrop. Monogr. 66: 560. (Published by NYBG Press)
Family:

Ericaceae
Synonyms:

Arctostaphylos novoleontis Rehder, Comarostaphylis minor Small, Arctostaphylos minor (Small) Standl.
Description:

Description - Erect to spreading, much-branched shrubs, 1-4 m tall; young twigs and petioles subglabrous to puberulent or tomentulose, trichomes usually eglandular. Leaves plane to weakly revolute, 2.2-6.6 × 0.3-1.9 cm, lower surface nearly glabrous to puberulent. Inflorescences with rachis, pedicels, bracts, bracteoles, and calyx puberulent to tomentulose or slightly canescent, trichomes usually eglandular. Flowers with ovary glabrous. Fruit 4-7 mm in diam.

Discussion:

Subspecies minor is distinguished from the other subspecies of C. polifolia by the combination of its usually non-glandular petioles and inflorescences, glabrous ovaries, and typically non-revolute leaves, as well as by its geographical distribution. Several earlier authors have recognized the taxon at the specific level (Small, 1914; Standley, 1924; Rehder, 1935), but field observations and numerical analysis (Diggs, 1981, 1986b, 1987) indicate that the characters separating it from subsp, polifolia are not of sufficient constancy or magnitude to warrant recognition as a distinct species. The plants from Nuevo Leon, previously recognized as Arctostaphylos novoleontis, and those from Tamaulipas, described as Comarostaphylis minor, are essentially identical. A few individuals from Tamaulipas (e.g., González-Medrano et al. 9227, MEXU) are unusual in having glandular hirsute or hirtellous young twigs, petioles, and inflorescences. Individuals from San Luis Potosi morphologically approach C. mucronata; the latter is distinguished by its larger, often serrulate leaves and the much-branched, canescent inflorescences.

Distribution and Ecology: Subspecies minor is restricted to the Sierra Madre Oriental mountains of Nuevo Leon, Tamaulipas, and San Luis Potosi at 1600-2800 m elevation. The subspecies is typically found in dry, often degraded areas of "matorral xerofilo" (Rzedowski, 1978) but is also known from xeric forests dominated by Pinus cembroides. Associates include assorted Cactaceae, Arbutus xalapensis, Bursera sp., Cercis canadensis, Dodonaea viscosa, Juniperus flaccida, Nolina sp., Pinus nelsoni, Ptelea trifoliata, Quercus canbyi, Q. prinopsis, Q. glaucoides, Rhus pachyrrachis, and Ungnadia speciosa. While edaphic requirements appear variable, many collections are from calcareous areas. Flowering, Mar-Jul; fruiting, May

Distribution:

Mexico North America| Nuevo León Mexico North America| San Luis Potosí Mexico North America| Tamaulipas Mexico North America|