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)
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
Ericaceae
Synonyms:
Arbutus discolor Hook., Arctostaphylos discolor (Hook.) DC.
Arbutus discolor Hook., Arctostaphylos discolor (Hook.) DC.
Description:
Species Description - Erect to spreading evergreen shrubs to small trees to 1-10 m tall; bark peeling or flaking, reddish-brown to brown or gray; young twigs glabrous and usually glaucous, or tomentulose to tomentose, often red or reddish-purple. Leaves coriaceous, narrowly ovate to elliptic or oblong-elliptic, plane or slightly revolute,(1.4-)3.7-15.3 × (0.2-)l.1-5.4 cm,base tapering to cuneate, apex acute, margins serrulate to serrate or serrate-dentate, (subentire); upper surface glabrous, green and shining, or with slight pubescence and somewhat dull; lower surface glabrous, often very glaucous, or tomentulose to ferruginously tomentose; petioles 6-19 mm long, glabrous and often glaucous, or tomentulose to tomentose, often red or reddish-purple. Inflorescences racemose, the racemes clustered, or paniculate, to 3.5-15 cm long, glabrous or tomentulose to tomentose or glandular hirsute, trichomes glandular or not; floral bracts narrowly ovate to ovate, navicular to carinate, acuminate, (1.3-)2.5-8.2(-14) mm × 1.9-3.3 mm, often ciliate; pedicels 2.5-13 mm long; bracteoles basal to medial, acicular to narrowly ovate, (1.1-) 1.6-3.7 mm long, often ciliate. Flowers with calyx lobes triangular or ovate-triangular, (1 -) 1.4-3.1 × 1-2.2 mm, acute to acuminate, glabrous or pubescent, trichomes glandular or not, often ciliate; corolla cream or white or pink, (4.5-)4.9-8.6 × (3.7-) 4.9-6.9 mm, glabrous or with hyaline trichomes; lobes 0.9-1.7 × (1.4-) 1.7-2.3 mm; stamens 2.5-3.7 mm long; filaments 2.3-3.3 mm long, villous; anthers 1-1.8 × 0.7-1 mm, spurs 0.3-0.8 mm long; ovary glabrous, style 2.4-3.7 mm long, glabrous. Fruit (5-)6-8 mm in diam., red when immature, dark purple to black at maturity; seeds 1.9-2.6 × 1.2-1.4 mm, surface reticulate.
Species Description - Erect to spreading evergreen shrubs to small trees to 1-10 m tall; bark peeling or flaking, reddish-brown to brown or gray; young twigs glabrous and usually glaucous, or tomentulose to tomentose, often red or reddish-purple. Leaves coriaceous, narrowly ovate to elliptic or oblong-elliptic, plane or slightly revolute,(1.4-)3.7-15.3 × (0.2-)l.1-5.4 cm,base tapering to cuneate, apex acute, margins serrulate to serrate or serrate-dentate, (subentire); upper surface glabrous, green and shining, or with slight pubescence and somewhat dull; lower surface glabrous, often very glaucous, or tomentulose to ferruginously tomentose; petioles 6-19 mm long, glabrous and often glaucous, or tomentulose to tomentose, often red or reddish-purple. Inflorescences racemose, the racemes clustered, or paniculate, to 3.5-15 cm long, glabrous or tomentulose to tomentose or glandular hirsute, trichomes glandular or not; floral bracts narrowly ovate to ovate, navicular to carinate, acuminate, (1.3-)2.5-8.2(-14) mm × 1.9-3.3 mm, often ciliate; pedicels 2.5-13 mm long; bracteoles basal to medial, acicular to narrowly ovate, (1.1-) 1.6-3.7 mm long, often ciliate. Flowers with calyx lobes triangular or ovate-triangular, (1 -) 1.4-3.1 × 1-2.2 mm, acute to acuminate, glabrous or pubescent, trichomes glandular or not, often ciliate; corolla cream or white or pink, (4.5-)4.9-8.6 × (3.7-) 4.9-6.9 mm, glabrous or with hyaline trichomes; lobes 0.9-1.7 × (1.4-) 1.7-2.3 mm; stamens 2.5-3.7 mm long; filaments 2.3-3.3 mm long, villous; anthers 1-1.8 × 0.7-1 mm, spurs 0.3-0.8 mm long; ovary glabrous, style 2.4-3.7 mm long, glabrous. Fruit (5-)6-8 mm in diam., red when immature, dark purple to black at maturity; seeds 1.9-2.6 × 1.2-1.4 mm, surface reticulate.
Discussion:
Comarostaphylis discolor is characterized by the usually large, narrowly ovate to elliptic, distinctly toothed leaf blades, and by its eglandular glabrous to pubescent twigs and petioles. The species is closely related to C. longifolia, from which it can be most easily distinguished by the glandular hirsute petioles of the latter. Comarostaphylis discolor is also similar to C. spinulosa, but in the area of sympatry (Oaxaca), the foliage of C. discolor (subsp. discolor) is glabrous, while C. spinulosa has pubescent abaxial leaf surfaces, petioles, and twigs, as well as smaller and usually more ovate to obovate leaf blades. Comarostaphylis discolor additionally shows affinities with C. arbutoides, with the characters separating them including the entire lamina margins and the usually more densely floriferous inflorescences of C. arbutoides. Where the two are sympatric, they can readily be distinguished by the glabrous abaxial leaf surfaces of C. discolor subsp. discolor (vs. tomentose).Four subspecies are recognized within Comarostaphylis discolor. The widespread subsp. discolor has long been treated as C. arguta, but the epithet discolor has priority (Diggs, 1982). This subspecies is distinguished by its glabrous young twigs, petioles, and lower leaf blade surfaces. Subspecies rupestris has traditionally been recognized at the specific level, but aside from having eglandular indumentum on the abaxial leaf surfaces, petioles, twigs, and inflorescences, the taxon is very similar to subsp. discolor. Subspecies manantlanensis, known only from the Sierra de Manantlan of Jalisco, is also distinguished primarily on the basis of pubescence characters, having eglandular indumentum on the foliage and glandular trichomes on the inflorescences. In addition to the variation encompassed by these three subspecies, additional variation in leaf size and pubescence is also found, particularly in Jalisco. In the Sierra de Tapalpa of S Jalisco, a population with glabrous, usually very small, sometimes entire leaves, is found and is recognized as subsp. macvaughii. A few individuals with pubescence characters that do not easily fit into any of the described subspecies are also known from Jalisco (Diaz L. 3811, MICH; Gregory & Eiten 250, MEXU, MICH, MO; Jones 300, MSC, MO, RSA, US; McVaugh 14376, MICH; Rzedowski 27557, ENCB). These indiviuals are clearly within the range of variation of C. discolor, and, while tentatively annotated as aff. subsp. discolor, in terms of morphological relationships they fall somewhere between subsp. discolor and the geographically distinct subsp. rupestris (Diggs, 1987).
Comarostaphylis discolor is characterized by the usually large, narrowly ovate to elliptic, distinctly toothed leaf blades, and by its eglandular glabrous to pubescent twigs and petioles. The species is closely related to C. longifolia, from which it can be most easily distinguished by the glandular hirsute petioles of the latter. Comarostaphylis discolor is also similar to C. spinulosa, but in the area of sympatry (Oaxaca), the foliage of C. discolor (subsp. discolor) is glabrous, while C. spinulosa has pubescent abaxial leaf surfaces, petioles, and twigs, as well as smaller and usually more ovate to obovate leaf blades. Comarostaphylis discolor additionally shows affinities with C. arbutoides, with the characters separating them including the entire lamina margins and the usually more densely floriferous inflorescences of C. arbutoides. Where the two are sympatric, they can readily be distinguished by the glabrous abaxial leaf surfaces of C. discolor subsp. discolor (vs. tomentose).Four subspecies are recognized within Comarostaphylis discolor. The widespread subsp. discolor has long been treated as C. arguta, but the epithet discolor has priority (Diggs, 1982). This subspecies is distinguished by its glabrous young twigs, petioles, and lower leaf blade surfaces. Subspecies rupestris has traditionally been recognized at the specific level, but aside from having eglandular indumentum on the abaxial leaf surfaces, petioles, twigs, and inflorescences, the taxon is very similar to subsp. discolor. Subspecies manantlanensis, known only from the Sierra de Manantlan of Jalisco, is also distinguished primarily on the basis of pubescence characters, having eglandular indumentum on the foliage and glandular trichomes on the inflorescences. In addition to the variation encompassed by these three subspecies, additional variation in leaf size and pubescence is also found, particularly in Jalisco. In the Sierra de Tapalpa of S Jalisco, a population with glabrous, usually very small, sometimes entire leaves, is found and is recognized as subsp. macvaughii. A few individuals with pubescence characters that do not easily fit into any of the described subspecies are also known from Jalisco (Diaz L. 3811, MICH; Gregory & Eiten 250, MEXU, MICH, MO; Jones 300, MSC, MO, RSA, US; McVaugh 14376, MICH; Rzedowski 27557, ENCB). These indiviuals are clearly within the range of variation of C. discolor, and, while tentatively annotated as aff. subsp. discolor, in terms of morphological relationships they fall somewhere between subsp. discolor and the geographically distinct subsp. rupestris (Diggs, 1987).
Distribution:
Mexico North America| Guatemala Central America|
Mexico North America| Guatemala Central America|