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:
Xolisma squamulosa Small
Xolisma squamulosa Small
Description:
Species Description - Evergreen, rhizomatous shrub to 3(-5) m tall, usually from underground woody burl or swelling, spreading vegetatively by horizontal underground rhizomes, with longitudinally furrowed bark; twigs slightly to moderately angled, slender, ± sparsely lepidote, otherwise very sparsely to densely pubescent; buds ovoid, 1-2 × ca. 1 mm. Leaf blades elliptic to ovate or obovate, 1-6.7 × 0.5-3.5 cm, sometimes quite strongly reduced in size toward branch tips, ± flat to very slightly recurved to concave, coriaceous, ca. 0.17-0.26 mm thick; base attenuate, narrowly to broadly cuneate (rounded); apex acuminate, acute to rounded; margin usually plane or very slightly revolute, apical portion entire (very obscurely and irregularly toothed), basal portion entire; venation brochidodromous, 3° veins ± reticulate; adaxial surface lepidote but scales quickly deciduous; slightly to densely pubescent on midvein, especially basal portion, the midvein usually not depressed, the 2° veins visible to obscure, usually not depressed, the 3° and higher-order veins slightly visible to obscure; abaxial surface moderately to densely lepidote, otherwise usually glabrous (with a few hairs on mid vein, or very sparsely to densely pubescent throughout), the 3° and higher-order veins flat or nearly so, very slightly and laxly reticulate to obscure, the 2° veins visible to obscure; scales rust colored to dark orange or brownish, sometimes becoming whitish with age, ± persistent, ca. 0.08-0.25 mm in diam., erose to entire; petiole 2-9 mm long, lepidote, otherwise pubescent adaxially to occasionally all around; flower buds ± intermixed with vegetative buds. Inflorescences fasciculate, 2-10-flowered; pedicels clearly articulated with calyx, slender, 4-14 mm long, lepidote, otherwise glabrous to sparsely pubescent; bracteoles subopposite, basal or nearly so, narrowly triangular, 0.7-1.5 mm long; floral bracts to ca. 2 mm long. Flowers (4-)5 (-6)-merous; calyx lobes triangular, with acuminate apices, 1-2 × 0.5-1.8 mm, adaxial side sparsely to moderately pubescent, especially near apex or margins, abaxial side lepidote, otherwise glabrous or very sparsely pubescent near base; corolla urceolate, white, 2.5-5 × 2.5-4.5 mm, abaxially sparsely lepidote; filaments roughened, 1.3-2.5 mm long, unappendaged or with pair of minute spurs near anther-filament junction; anthers 0.7-1.3 mm long; ovary lepidote, otherwise pubescent, placentae ± subapical. Capsules usually subglobose to short-ovoid, 2.5-4(-5) × 2.5-4.5 mm, sparsely lepidote, otherwise usually sparsely pubescent, especially near base, the pale, very thick sutures separating as unit from adjacent valves (with additional pale lines alternating with and resembling sutures); seeds 1-2 mm long.
Species Description - Evergreen, rhizomatous shrub to 3(-5) m tall, usually from underground woody burl or swelling, spreading vegetatively by horizontal underground rhizomes, with longitudinally furrowed bark; twigs slightly to moderately angled, slender, ± sparsely lepidote, otherwise very sparsely to densely pubescent; buds ovoid, 1-2 × ca. 1 mm. Leaf blades elliptic to ovate or obovate, 1-6.7 × 0.5-3.5 cm, sometimes quite strongly reduced in size toward branch tips, ± flat to very slightly recurved to concave, coriaceous, ca. 0.17-0.26 mm thick; base attenuate, narrowly to broadly cuneate (rounded); apex acuminate, acute to rounded; margin usually plane or very slightly revolute, apical portion entire (very obscurely and irregularly toothed), basal portion entire; venation brochidodromous, 3° veins ± reticulate; adaxial surface lepidote but scales quickly deciduous; slightly to densely pubescent on midvein, especially basal portion, the midvein usually not depressed, the 2° veins visible to obscure, usually not depressed, the 3° and higher-order veins slightly visible to obscure; abaxial surface moderately to densely lepidote, otherwise usually glabrous (with a few hairs on mid vein, or very sparsely to densely pubescent throughout), the 3° and higher-order veins flat or nearly so, very slightly and laxly reticulate to obscure, the 2° veins visible to obscure; scales rust colored to dark orange or brownish, sometimes becoming whitish with age, ± persistent, ca. 0.08-0.25 mm in diam., erose to entire; petiole 2-9 mm long, lepidote, otherwise pubescent adaxially to occasionally all around; flower buds ± intermixed with vegetative buds. Inflorescences fasciculate, 2-10-flowered; pedicels clearly articulated with calyx, slender, 4-14 mm long, lepidote, otherwise glabrous to sparsely pubescent; bracteoles subopposite, basal or nearly so, narrowly triangular, 0.7-1.5 mm long; floral bracts to ca. 2 mm long. Flowers (4-)5 (-6)-merous; calyx lobes triangular, with acuminate apices, 1-2 × 0.5-1.8 mm, adaxial side sparsely to moderately pubescent, especially near apex or margins, abaxial side lepidote, otherwise glabrous or very sparsely pubescent near base; corolla urceolate, white, 2.5-5 × 2.5-4.5 mm, abaxially sparsely lepidote; filaments roughened, 1.3-2.5 mm long, unappendaged or with pair of minute spurs near anther-filament junction; anthers 0.7-1.3 mm long; ovary lepidote, otherwise pubescent, placentae ± subapical. Capsules usually subglobose to short-ovoid, 2.5-4(-5) × 2.5-4.5 mm, sparsely lepidote, otherwise usually sparsely pubescent, especially near base, the pale, very thick sutures separating as unit from adjacent valves (with additional pale lines alternating with and resembling sutures); seeds 1-2 mm long.
Discussion:
Lyonia squamulosa is very closely related to L. ferruginea and L. fruticosa of the southeastern United States. It is clearly separated from L. fruticosa by the usual absence of unicellular hairs and the more or less persistent peltate scales on the abaxial leaf surface (vs. usually pubescent, with ± deciduous scales), the usually shorter and more or less subglobose capsules (i.e., 2.5-4 mm vs. 3-5 mm), and the lower frequency of plants having the leaves strongly reduced in size toward the branch apices. Lyonia squamulosa can be differentiated from L. ferruginea by the usual absence of unicellular hairs on the abaxial leaf surfaces (vs. pubescent), the plane or only slightly (vs. slightly to strongly) revolute leaf margins, the absence of noticeable depression of the major leaf veins (vs. such veins usually depressed), and the usually shorter, subglobose capsules (i.e., 2.5-4 mm vs. 3-6 mm). Lyonia squamulosa also has a tendency to have darker orange or brown peltate scales, and its leaves are more often elliptic or ovate (see also Judd, 1981).Lyonia squamulosa is extremely variable in leaf shape and size, apex form, degree of reduction in leaf size toward branch apices, and in pubescence. Some plants have large, elliptic leaves with acute or acuminate apices, while others have small, more or less obovate ones with rounded to acute apices; the former superficially resemble L. ferruginea, the latter L. fruticosa. All sorts of intermediate individuals occur, however, and even within single populations a wide variability in leaf shape and size is evident, e.g., Pringle 13096. Although most specimens lack unicellular hairs on the abaxial leaf surfaces, a few (especially those from San Luis Potosi- see Judd, 1981) show a very slight to dense covering of such hairs. These specimens can sometimes be confused with L. fruticosa. Strongly revolute leaves, another unusual character in L. squamulosa, are present on Rzedowski 5451, also collected in San Luis Potosi.
Lyonia squamulosa is very closely related to L. ferruginea and L. fruticosa of the southeastern United States. It is clearly separated from L. fruticosa by the usual absence of unicellular hairs and the more or less persistent peltate scales on the abaxial leaf surface (vs. usually pubescent, with ± deciduous scales), the usually shorter and more or less subglobose capsules (i.e., 2.5-4 mm vs. 3-5 mm), and the lower frequency of plants having the leaves strongly reduced in size toward the branch apices. Lyonia squamulosa can be differentiated from L. ferruginea by the usual absence of unicellular hairs on the abaxial leaf surfaces (vs. pubescent), the plane or only slightly (vs. slightly to strongly) revolute leaf margins, the absence of noticeable depression of the major leaf veins (vs. such veins usually depressed), and the usually shorter, subglobose capsules (i.e., 2.5-4 mm vs. 3-6 mm). Lyonia squamulosa also has a tendency to have darker orange or brown peltate scales, and its leaves are more often elliptic or ovate (see also Judd, 1981).Lyonia squamulosa is extremely variable in leaf shape and size, apex form, degree of reduction in leaf size toward branch apices, and in pubescence. Some plants have large, elliptic leaves with acute or acuminate apices, while others have small, more or less obovate ones with rounded to acute apices; the former superficially resemble L. ferruginea, the latter L. fruticosa. All sorts of intermediate individuals occur, however, and even within single populations a wide variability in leaf shape and size is evident, e.g., Pringle 13096. Although most specimens lack unicellular hairs on the abaxial leaf surfaces, a few (especially those from San Luis Potosi- see Judd, 1981) show a very slight to dense covering of such hairs. These specimens can sometimes be confused with L. fruticosa. Strongly revolute leaves, another unusual character in L. squamulosa, are present on Rzedowski 5451, also collected in San Luis Potosi.
Distribution and Ecology: (Fig. 28). Mexico, E Sierra Madre from Nuevo Leon southeast to Veracruz, Puebla, and Oaxaca, Chiapas, and Guerrero. Temperate montane regions, mostly 1000-2400 m elev. Listed by Miranda and Sharp (1950) as an understory shrub of mixed oak and/or pine forests; important in some disturbed communities following destruction of original forest by timber cutting, agriculture, or fire. In studies of vegetation of San Luis Potosi, G. C. Rzedowski (1960) and J. Rzedowski (1966) listed this species as a characteristic component of "encinar arbustivo" (chaparral of Quercus, Arctostaphylos, Cercocarpus, Amelanchier, Garrya, Salvia, Rhus, Yucca), "piñonar" (forest of Pinus cembroides), and "encinar y pinar" (Pinus and Quercus forests). Also collected from floristically diverse Pinus, Quercus, and Liquidambar forest of Montebello, Chiapas, described by Carlson (1954); occasionally collected in "bosque deciduo templado" of Sierra Madre Oriental. This forest type is described in Miranda and Sharp (1950) and J. Rzedowski (1966). Although not yet known from Guatemala, it may grow there because it has been collected in an adjacent area of Chiapas. Flowering throughout year but especially March through June.
Distribution:
Mexico North America| Chiapas Mexico North America| Guerrero Mexico North America| Hidalgo Mexico North America| Nuevo León Mexico North America| Oaxaca Mexico North America| Puebla Mexico North America| San Luis Potosí Mexico North America| Tamaulipas Mexico North America| Veracruz Mexico North America|
Mexico North America| Chiapas Mexico North America| Guerrero Mexico North America| Hidalgo Mexico North America| Nuevo León Mexico North America| Oaxaca Mexico North America| Puebla Mexico North America| San Luis Potosí Mexico North America| Tamaulipas Mexico North America| Veracruz Mexico North America|