Miconia zanonii Judd, Skean & R.S.Beaman

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: DOMINICAN REPUBLIC. Prov. La Vega: Cordillera Central, Loma la Golondrina, E of Paso Bajito and S of Loma la Sal, SE of Jarabacoa, ca 1500-1565 m, in diverse cloud forest near peak, young fr, 23 May 1986, W. Judd 5158 (holotype: FLAS!; isotypes: A!, F!, JBSD!, MO!, NY!, S!, US!).

Description: Shrub to ca 3 m tall. Indumentum of multicellular, minute, globular hairs, as well as irregularly stellate-branched hairs. Young twigs elliptic, (2.5-) 3-7 mm wide, sulcate, with very slight nodal ridge, becoming terete with age, usually densely covered with multicellular, ferrugineous, globular to irregularly stellate-branched hairs, glabrescent; internodes 1-5 (-9) cm long. Leaves with petiole 0.9-2.8 cm long, with indumentum similar to that of twigs; blade 5-12 (-16) cm long, 1.8-5 (-5.5) cm wide (but pair immediately below inflorescence usually smaller and sometimes intergrading with inflorescence bracts), elliptic to ovate or obovate, coriaceous, the apex slightly acuminate to acute or obtuse, the base rounded to obtuse, the margin plane, obscurely to clearly serrate, the largest teeth 0.2-0.5 mm long, becoming entire near base, ca 10-50% of margin entire; venation acrodromous, basal, with prominent midvein and 4 secondary veins, with 2 conspicuous secondary veins placed ca 2.5-6.5 (-9) mm in from margin and 2 inconspicuous intramarginal secondary veins, and numerous percurrent tertiary veins oriented subperpendicular to midvein, the tertiary veins joined by percurrent-orthogonal quaternary veins; adaxial surface green, sometimes slightly red-tinged near margin, densely covered with minute globular, and irregularly branched, multicellular hairs, glabrescent, the midvein and 2 major secondary veins impressed, 2 minor secondary veins and tertiary veins slightly impressed to flat, the surface ± papillose after drying due to presence of numerous druse crystals; abaxial surface light green to red-tinged (especially near margin), initially densely covered with minute globular hairs on lamina and ferrugineous, irregularly stellate-branched hairs on veins, becoming only sparsely globular-pubescent on mature leaves (glabrescent), the midvein and 2 major secondary veins prominently raised, the 2 intramarginal secondary veins and tertiary veins slightly to not at all raised. Inflorescences many-flowered, open, broadly rounded cymes of 3 or 4 major branch-pairs, ca 2.5-5 cm long, 3.5-6.5 mm across; proximal segment of lowermost inflorescence branches 0.8-1.9 cm long, distal internodes of inflorescence branches increasingly shorter, the ultimate branches 1.5-5 mm long, glabrous to sparsely covered with minute globular hairs; peduncle 1.5-7.5 mm long, with similar indumentum; each inflorescence branch associated with a caducous, broadly ovate to elliptic, often reddish bract, ca 8-18 mm long, 5.5-10 mm wide, the apices acute to rounded; flowers in dichasia, each subtended by 2 caducous, broadly ovate to obovate, often reddish, bracteoles, ca 4-11.5 mm long, 2.5-9 mm wide, nearly glabrous but with a few irregularly branched hairs near margins, their apices rounded. Flowers nearly sessile. Hypanthium ± cylindrical, free portion 1.4-2.5 mm long, the outer surface sparsely covered with minute, ferrugineous, globular hairs, the inner surface glabrous and 10-ridged, the apices of the ridges forming minute projections 0.1-0.2 mm long. External calyx lobes 5, 0.7-1.1 mm long, 1.9-2.6 mm wide, broadly triangular with acute to slightly acuminate apex, very sparsely covered with indumentum similar to that of hypanthium; internal calyx lobes 5, 1-1.1 mm long, 2.3-2.4 mm wide, broadly ovate-triangular, pale green, often red-tinged, glabrous on both surfaces, the apex rounded, the margin entire; calyx tube ca 0.3 mm long. Petals 5, 2.4-2.8 mm long 2.7-3.2 mm wide, broadly elliptic to slightly ovate or obovate, white, glabrous; margin entire. Stamens 10, geniculate, white; proximal segment ca 1 mm long; distal segment ca 2.7 mm long, anther ca 1.9 mm long, with fertile portion of anther sacs ca 1.4 mm long, with a dorsal bump ca 0.1 mm long, the connective/distal part of filament extending 0.7-0.8 mm beyond the base of anther sacs. Ovary 5-loculate, 3/4 to nearly completely inferior, ca 2.7 mm long, 2.5-3 mm in diameter, ± globose, glabrous and 10-ridged, with minute apical projections, to ca 0.1 mm long, encircling base of style; style 2.5-3.2 mm long, glabrous; stigma truncate. Nearly mature berries ca 6-8 mm in diameter (possibly larger when fully mature), globose, purple (red when immature, and probably blue when fully mature), with very sparsely scattered globular hairs. Seeds ca 0.5-0.7 mm long, angular-obovoid; testa smooth. Figs. 18, 19.

Habitat and Distribution: Hispaniola (Dominican Republic), Cordillera Central; cloud forests (or moist thickets); 1400 to 2075 m. Associated melastomes include: Clidemia umbellata, Mecranium puberulum Cogn., Meriania involucrata (Desr.) Naudin, Leandra lima (Desr.) Judd & Skean, L. limoides (Urb.) Judd & Skean, Miconia adenocalyx, M. desportesii Urb., M. dodecandra (Desr.) Cogn., M. punctata (Desr.) D. Don, M. tetrastoma, Sagraea fuertesii (Cogn.) Alain, S. oligantha (Urb.) Alain, and Tetrazygia crotonifolia (Desr.) DC. (see also Judd et al., 1988). The vegetation of Loma la Golondrina and vicinity is described in detail by García et al. (1994) and Mejía et al. (2000).

Phenology: Flowering recorded from April, October, and November, but probably blooming more frequently.

Taxonomy and Systematics: Miconia zanonii is possibly closely related to M. calycina, and these two species share the putative apomorphies of the abaxial surface of the mature leaves with usually only minute globular hairs, rounded cymes, 5-loculate ovaries, and large berries. It can easily be distinguished from M. calycina by the shorter calyx tube (i.e., ca 0.3 mm) that does not tear longitudinally between the calyx lobes (vs. tube 0.6-1.2 mm long and longitudinally tearing), broadly ovate calyx lobes, ca 1-1.1 mm long (vs. ovate-oblong, oblong, or obovate lobes, 1.2-2.6 mm long), and anthers only distally fertile (vs. fertile nearly throughout. Miconia barkeri may also be related, and its mature leaves, like those of M. zanonii, are nearly glabrescent. Miconia barkeri is easily distinguished from both M. zanonii and M. calycina by the presence of hair tuft mite-domatia (see also key). Miconia zanonii is geographically isolated from both M. calycina and M. barkeri (Figs. 20, 23). Miconia zanonii has also been compared to members of the falcate-leaved clade, e.g., M. krugii and M. samanensis (see Judd et al. 1988, and key, for detailed comparison), another group with glabrescent leaves. The leaves of M. krugii consistently dry a yellowish-green color, and it is noteworthy that the leaves of M. zanonii and M. calycina occasionally dry yellowish green. These three species are eco-geographically isolated (see also Judd et al. 1988). The species was first collected by E. Ekman in November of 1929, but he reported that none of the plants were in reproductive condition. It was not until 1988 that it was recognized as a distinct species (Judd et al. 1988).

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