Miconia barkeri Urb. & Ekman

Description

Description Author and Date: Walter S. Judd, 2010, based on Judd, W. S. (2007). Revision of Miconia sect. Chaenopleura (Melastomataceae) in the Greater Antilles. Systematic Botany Monographs 81:1-235.

Type: HAITI. Dept. du Sud: Massif de la Hotte, Torbec, summit of high ridge above La Mare-Proux, ca 1780 m alt., fl, 8 Dec 1925, E. L. Ekman H5329 (holotype: S!; isotypes: EHH, NY!, US!).

Description: Shrub or small tree to 4 m tall. Indumentum of multicellular, very pale ferrugineous, appressed, stellate-peltate scales, these quickly degenerating and sometimes appearing as minute globular hairs, and long-stalked, gland-headed hairs to 1.4 mm long. Young twigs not ridged, ± rectangular in cross-section, 3-7 mm wide, becoming ± terete with age, the indumentum of moderate to dense, appressed, stellate-peltate scales, these quickly degenerating, and sparse long-stalked, gland-headed hairs at and just distal to the nodes; internodes 1-4.3 (-7.4) cm long. Leaves with petiole 0.8-3.8 (-5) cm long, the indumentum sparse to moderate appressed and quickly degenerating, stellate-peltate scales along with long-stalked, gland-headed hairs scattered along 2 adaxial ridges; blade 4-12.3 (-20) cm long, 2-7 (-10) cm wide, ovate to obovate, flat, coriaceous, the apex acuminate to shortly so, the base acute to rounded, the margin plane to sometimes slightly revolute near base, serrulate, especially distally, ca 0-22% of margin entire, the largest teeth 0.2-0.5 mm long, those near base very occasionally associated with a long-stalked, gland-headed hair (but most teeth associated with such hairs on leaves of young seedlings); venation acrodromous, ± basal, with prominent midvein and 4 or 6 secondary veins, with 2 most conspicuous secondary veins placed 3-12 (-19) mm in from margin, with 2 or 4 less conspicuous to very inconspicuous secondary veins closer to margin, and numerous percurrent tertiary veins oriented subperpendicular to midvein, the tertiary veins connected by ± percurrent quaternary veins, higher-order veins ± orthogonal reticulate; adaxial surface green, the indumentum initially of scattered, appressed, quickly-degenerating, stellate-peltate scales, but very quickly glabrescent or appearing to be only sparsely covered with minute globular hairs, and in seedling leaves also with very sparse long-stalked, gland-headed hairs, the midvein and major secondary veins impressed, minor secondary veins very slightly impressed to flat, tertiary and higher-order veins ± flat, the surface appearing ± minutely papillose after drying due to presence of scattered druse crystals; abaxial surface pale green with midvein and secondary veins often reddish, moderately covered with quickly degenerating, appressed, stellate-peltate scales, these sometimes appearing as minute globular hairs, on veins and lamina surface, to ca 0.1-0.15 mm across, but often somewhat smaller on major veins, with very sparsely scattered long-stalked, gland-headed hairs along midvein and similar hairs densely clustered in axils of midvein and secondary veins, forming domatia, the midvein prominently raised, major secondary veins prominently to slightly raised, minor secondary veins slightly raised to flat, tertiary veins very slightly raised to flat, remaining veins flat.

Description (cont.): Inflorescences many-flowered broadly rounded cymes of 2 to 4 major branch pairs, 4.2-9 cm long, 3-8.2 cm across; proximal segment of lowermost inflorescence branches 1-2.5 cm long, distal internodes shorter, ultimate branches 3.3-10 mm long, with sparse, appressed, quickly-degenerating, stellate-peltate scales; peduncle 1.3-4.2 cm long, with similar indumentum; each inflorescence branch associated with early caducous, ovate to narrowly elliptic or oblong bract, ca 8-15 mm long, 1.5-3 mm wide, the apices ± acute, the lower pair sometimes expanded and leaf-like; flowers in dichasia, ± distinctly separated from each other, each subtended by 2 caducous, ovate to obovate bracteoles 3-7.5 mm long, 1.3-3 mm wide, the indumentum of sparse appressed ± peltate scales, their apices acute. Flowers shortly pedicellate, the pedicel 0.5-2 mm long. Hypanthium cylindrical, free portion ca 1.6-2 mm long, the outer surface with sparse, minute, appressed, ± degenerating, stellate-peltate scales, the inner surface with scattered short- to long-stalked, gland-headed hairs 0.05-0.3 mm long, especially at apex of hypanthium near point of stamen attachment, slightly to clearly 10-ridged (sometimes with less prominent ridges between the major ones), the apices of the ridges not to only slightly projecting, to 0.14 mm. External calyx lobes 5, 0-0.5 mm long, 2-2.9 mm wide, ± obsolete to broadly triangular, with ± obtuse apex, indumentum of sparse hairs similar to those of hypanthium, and with 1 to few multicellular, elongate hairs at or near apex, these to 0.1-0.6 mm long, with hair base intergrading with lobe apex, thus external calyx lobes often appearing longer than they actually are, with apex appearing ± acuminate to irregularly fimbriate, sometimes lobe obsolete and only represented by 1 to few such hairs; internal calyx lobes 5, 0.6-1.6 mm long, 2-2.9 mm wide, ovate-triangular, green to reddish, glabrous, the apex rounded to obtuse, the margin entire and minutely fringed with branched hairs; calyx tube 0.45-0.8 mm long. Petals 5, 5-6.7 mm long, 3.8-5 mm wide, broadly ovate to obovate, glabrous, white, sometimes pink tinged; margin entire. Stamens 10, geniculate; proximal segment 2.4-3.8 mm long; distal segment 3.3-4.1 mm long, with minute dorsal projection, the anther 2.3-2.9 mm long, with fertile portion of anther sacs 1.3-1.8 mm long, the connective/distal part of filament extended 0.65-1.4 mm beyond the base of the anther sacs. Ovary 2- to 4-loculate (with the 3-loculate condition the most common), ca 2/3 to 3/4-inferior, ca 3.3-4.3 mm long, 4.8-5.7 mm in diameter, shortly obovoid, glabrous, except for a few short- to long-stalked, gland-headed hairs at apex, and slightly ridged, with fluted apical projection to 0.4-0.6 mm encircling the base of style; style 4.5-5 mm long, glabrous; stigma truncate. Berries ca 6 mm long, 7 mm in diameter, ellipsoid to ± globose, red when immature and turning blue at maturity, with ± sparse, appressed, stellate-peltate scales. Seeds ca 0.9-1.2 mm long, angular-obovoid; testa smooth. Figs. 24, 25.

Habitat and Distribution: Hispaniola (Haiti), Massif de la Hotte; cloud forests and moist forests of Pinus occidentalis; ca 1800-2200 m. Associated melastomes include Henriettea barkeri, Mecranium alpestre Urb. & Ekman, M. tricostatum, M. tuberculatum, Meriania squamulosa, Miconia alloeotricha, M. apiculata, M. hypiodes, M. subcompressa, M. tetrastoma, and M. xenotricha. The vegetation and flora of these forests is described in more detail in Judd (1987) and Judd et al. (1990, 1998).

Phenology: Recorded as flowering in December, January, and June, but probably blooming nearly throughout year.

Taxonomy and Systematics: Miconia barkeri may be related to M. calycina and M. zanonii (see discussion under those species) or the Cuban endemics, M. alternifolia, M. skeaniana, and M. cubensis. Finally, some individuals of M. barkeri have somewhat elongated ultimate inflorescence branches (i.e., the longest to 3.3-10 mm), and this characteristic may suggest a phylogenetic relationships with the members of the lax inflorescence clade, i.e., M. adenocalyx, M. ferruginea, M. pseudorigida, M. rigida, and M. santanana. It is easily distinguished from all of these species by its leaves abaxially with conspicuous clusters of long-stalked, gland-headed hairs forming mite-domatia, at the junctions of the major secondary veins with the midvein, and provided with appressed and quickly degenerating stellate-peltate scales. Both domatia and peltate scales are lacking in the above listed species (which have minute-globular to stellate or globular-stellate hairs). Both M. barkeri and M. rigida are distinctive in having the inner surface of the hypanthium with scattered stalked, gland-headed hairs, especially at the apex; the remaining above listed species have glabrous inner hypanthial surfaces. Miconia calycina, M. rigida and M. pseudorigida (the latter two members of the lax inflorescence clade), and sometimes M. alternifolia, like M. barkeri, have anthers that are fertile nearly to the base. Many of these species also have rounded cymes. Miconia barkeri is geographically isolated from all of these species because it is restricted to the Massif de la Hotte, Haiti. Miconia barkeri was known from only two gatherings made by E. L. Ekman, until recollected in the Parc National Pic Macaya by J. D. Skean, Jr. and myself during several trips to the Massif de la Hotte, Haiti. The additional specimens have clarified the pattern of variation within this species, and resulted in the first description of its fruits and seeds.

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Miconia barkeri: Botanical line drawing. (image/jpeg)