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 orbiculata Sleumer, Lyonia orbiculata (Sleumer) Jiménez
Xolisma orbiculata Sleumer, Lyonia orbiculata (Sleumer) Jiménez
Description:
Species Description - Evergreen, low, spreading shrub to ca. 0.5 m tall, with gray, longitudinally furrowed bark; twigs slightly angled, slender to stout, moderately lepidote, otherwise glabrous or very sparsely pubescent; buds ovoid, 1-2 x 1-1.8 mm. Leaf blades ovate to broadly elliptic to orbicular, 1.1-3.1 × 0.9-2.6 cm, ± flat, coriaceous, ca. 0.5-0.6 mm thick; base rounded to widely cuneate; apex truncate or rounded to nearly acute; margin plane to sometimes slightly revolute, apical portion obscurely and irregularly toothed, basal portion toothed to entire; venation brochidodromous, 3° veins ± reticulate; adaxial surface lepidote but scales usually quickly deciduous, sparsely pubescent on basal portion of midvein, veins obscure to sometimes faintly visible; abaxial surface moderately to densely lepidote, otherwise densely pubescent, with 2° and higher-order veins usually obscure or nearly so (only very rarely raised and forming dense, fine reticulum); scales rust colored, persistent to deciduous, ca. 0.08-0.2 mm in diam., usually ± erose; petiole 3-5 mm long, lepidote, otherwise adaxially pubescent; flower buds ± intermixed with vegetative buds. Inflorescences fasciculate, ca. 5-8-flowered; pedicels clearly articulated with calyx, slender, 2-6 mm long, lepidote, otherwise glabrous or very sparsely pubescent; bracteoles ± opposite, basal, narrowly triangular, 1.5-2 mm long; floral bracts to ca. 2.5 mm long. Flowers 4-5-merous; calyx lobes triangular, with acuminate apices, 1.5-2 × 0.7-1.4 mm, adaxial side pubescent, especially near apex, abaxial side lepidote, otherwise glabrous; corolla cylindrical, white, 5-6.5 × 3-4 mm, abaxially sparsely lepidote; filaments roughened, ca. 3.5 mm long, essentially unappendaged; anthers ca. 1.3 mm long; ovary lepidote, otherwise pubescent, placentae ± subapical. Capsules ± globose to short-ovoid, 3-4 × 3-4 mm, slightly lepidote, otherwise sparsely pubescent, especially near base, the pale, very thick sutures separating as unit from adjacent valves; seeds 1.4-2 mm long.
Species Description - Evergreen, low, spreading shrub to ca. 0.5 m tall, with gray, longitudinally furrowed bark; twigs slightly angled, slender to stout, moderately lepidote, otherwise glabrous or very sparsely pubescent; buds ovoid, 1-2 x 1-1.8 mm. Leaf blades ovate to broadly elliptic to orbicular, 1.1-3.1 × 0.9-2.6 cm, ± flat, coriaceous, ca. 0.5-0.6 mm thick; base rounded to widely cuneate; apex truncate or rounded to nearly acute; margin plane to sometimes slightly revolute, apical portion obscurely and irregularly toothed, basal portion toothed to entire; venation brochidodromous, 3° veins ± reticulate; adaxial surface lepidote but scales usually quickly deciduous, sparsely pubescent on basal portion of midvein, veins obscure to sometimes faintly visible; abaxial surface moderately to densely lepidote, otherwise densely pubescent, with 2° and higher-order veins usually obscure or nearly so (only very rarely raised and forming dense, fine reticulum); scales rust colored, persistent to deciduous, ca. 0.08-0.2 mm in diam., usually ± erose; petiole 3-5 mm long, lepidote, otherwise adaxially pubescent; flower buds ± intermixed with vegetative buds. Inflorescences fasciculate, ca. 5-8-flowered; pedicels clearly articulated with calyx, slender, 2-6 mm long, lepidote, otherwise glabrous or very sparsely pubescent; bracteoles ± opposite, basal, narrowly triangular, 1.5-2 mm long; floral bracts to ca. 2.5 mm long. Flowers 4-5-merous; calyx lobes triangular, with acuminate apices, 1.5-2 × 0.7-1.4 mm, adaxial side pubescent, especially near apex, abaxial side lepidote, otherwise glabrous; corolla cylindrical, white, 5-6.5 × 3-4 mm, abaxially sparsely lepidote; filaments roughened, ca. 3.5 mm long, essentially unappendaged; anthers ca. 1.3 mm long; ovary lepidote, otherwise pubescent, placentae ± subapical. Capsules ± globose to short-ovoid, 3-4 × 3-4 mm, slightly lepidote, otherwise sparsely pubescent, especially near base, the pale, very thick sutures separating as unit from adjacent valves; seeds 1.4-2 mm long.
Discussion:
Lyonia alpina is probably most closely related to L. microcarpa, L. urbaniana, and L. tinensis (see "Infrageneric Relationships") but is phylogenetically adjacent (and phenetically similar) to L. truncata; the two species have similarly shaped leaves with densely pubescent, obscurely veined abaxial surfaces and more or less smooth adaxial surfaces; large, more or less cylindrical corollas; and wide capsules. Lyonia alpina can be distinguished by its shorter, 4-5-merous capsules and its more coriaceous, more densely lepidote leaves. Lyonia alpina also is quite similar to L. microcarpa, as indicated by its often 4-merous flowers and its small and often densely ferruginous leaves. It can be differentiated from this species by the shape and size of its capsules, its long calyx lobes and corollas, and the obscure venation of its smooth abaxial leaf surface. Lyonia alpina occurs at elevations higher than those of any other species of the genus in the Massif de la Selle and is isolated elevationally from both L. truncata var. truncata and L. microcarpa.Recent collections from the vicinity of Pic la Selle (see above) indicate that the minor differences in leaf shape and apex used by Sleumer (1934b) in recognizing Lyonia orbiculata do not hold, and the species is considered here as a synonym of L. alpina (see also Judd, 1981).
Lyonia alpina is probably most closely related to L. microcarpa, L. urbaniana, and L. tinensis (see "Infrageneric Relationships") but is phylogenetically adjacent (and phenetically similar) to L. truncata; the two species have similarly shaped leaves with densely pubescent, obscurely veined abaxial surfaces and more or less smooth adaxial surfaces; large, more or less cylindrical corollas; and wide capsules. Lyonia alpina can be distinguished by its shorter, 4-5-merous capsules and its more coriaceous, more densely lepidote leaves. Lyonia alpina also is quite similar to L. microcarpa, as indicated by its often 4-merous flowers and its small and often densely ferruginous leaves. It can be differentiated from this species by the shape and size of its capsules, its long calyx lobes and corollas, and the obscure venation of its smooth abaxial leaf surface. Lyonia alpina occurs at elevations higher than those of any other species of the genus in the Massif de la Selle and is isolated elevationally from both L. truncata var. truncata and L. microcarpa.Recent collections from the vicinity of Pic la Selle (see above) indicate that the minor differences in leaf shape and apex used by Sleumer (1934b) in recognizing Lyonia orbiculata do not hold, and the species is considered here as a synonym of L. alpina (see also Judd, 1981).
Distribution:
Haiti South America|
Haiti South America|