Comarostaphylis spinulosa (M.Martens & Galeotti) Diggs

  • 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

  • Scientific Name

    Comarostaphylis spinulosa (M.Martens & Galeotti) Diggs

  • Description

    Species Description - Low, mat-forming, or upright, often densely branched shrubs (or small trees?) to 4(-6?) m tall; bark peeling and flaking, sometimes furrowed, gray to orange-gray; young twigs sometimes red, tomentulose to glandular hirsute, rarely nearly glabrate. Leaves coriaceous to slightly so, elliptic to ovate or obovate, plane, 2-7.4 × 0.8-3.7 mm, base cuneate, apex obtuse to acute, margins serrate to serrulate, rarely subentire, upper surface glabrate or with scattered glandular or eglandular trichomes, lower surface densely to sparsely ferruginously tomentulose or with dense white to ferruginous tomentum, rarely glabrate, midrib with eglandular or glandular trichomes; petioles 2-8 mm long, tomentulose to glandular-hirsute, rarely nearly glabrate. Inflorescences racemose or paniculate, 3.3-9.2 cm long, rachis, pedicels, bracts, and bracteoles tomentulose to glandular hirsute; floral bracts narrowly ovate, plane to slightly navicular or carinate, 0.3-1.1 (-2) × 0.4-2.5(-6) mm, often ciliate; pedicels 3-10(-14) mm long; bracteoles basal to supramedial, narrowly ovate, 2-5 mm long, ciliate or not. Flowers with calyx lobes triangular to broadly so, 1.7-2.5 × 1.3-1.8 mm, acute to acuminate, tomentulose, to glandular pubescent, or nearly glabrous, often ciliate; corollas greenish-white to white or pink, 5.8-7.4 × 4.1-5.8 mm, glabrous to pubescent, lobes 0.9-1.3 × 1.3-2 mm; stamens 2.3-3.2 mm long; filaments 2-3 mm long, villous; anthers 1.2-1.5 × 0.7-1 mm, spurs 0.6-1 mm long; ovary glabrous to pubescent; style 2.8-4.1 mm long, glabrous. Fruit red when immature, dark purple to black at maturity, 5-7 mm in diam.; seeds 2.3-2.7 × 1.1-1.4 mm, surface reticulate.

  • Discussion

    Small (1914) and Standley (1924) put Arctostaphylos spinulosa in synonymy with C. arguta Zucc. ( = C. discolor). However, the type specimen of Arctostaphylos spinulosa is clearly conspecific with the taxon that has been going under the name of C. conzattii, a later synonym. The species is closely related to C. discolor; one extreme of variation in subsp. spinulosa morphologically approaches C. discolor subsp. discolor with the major differences separating them being the larger, glabrous, and more elliptic leaves, and the usual lack of pubescence on the twigs and petioles of C. discolor subsp. discolor. However, on the basis of leaf size and shape, as well as pubescence characters and growth form, the relationship of subsp. spinulosa appears closer to subsp. glandulifera. An attempt to extend the circumscription of C. discolor to include these two subspecies would cause it to be so heterogeneous as to defy circumscription.

    Comarostaphylis spinulosa, composed of two allopatric subspecies, is distinguished by its pubescent young branches, petioles and abaxial leaf surfaces, by its small, usually ovate or obovate leaves, the typically small inflorescences, and by the often low growth habit.

    Distribution and Ecology: (Fig. 17) and ecology. Comarostaphylis spinulosa is confined to the mountains of Oaxaca and extreme S Puebla at (1800-)2100-3200 m elevation. The species is found in moist Quercus-Pinus forests with associates such as Arbutus xalapensis, Arctostaphylos pungens, Fuchsia sp., Gaultheria sp., Monnina xalapensis, Oreopanax xalapensis, Pernettya prostrata, Pinus pseudostrobus, Quercus brachystachya, Q. obtusata, Rhus trilobus, and Vaccinium sp. Flowering and fruiting throughout the year.