Miconia variabilis Gamba & Almeda

  • Family

    Melastomataceae (Magnoliophyta)

  • Scientific Name

    Miconia variabilis Gamba & Almeda

  • Primary Citation

    Systematics of the octopleura clade of Miconia (Melastomataceae: Miconieae) in tropical America
    Phytotaxa 179: 1--174. 2014

  • Description

    Description Author and Date: Diana Gamba & Frank Almeda, modified from "Systematics of the Octopleura Clade of Miconia (Melastomataceae: Miconieae) in Tropical America". Gamba, D., Almeda, F. Phytotaxa 179(1): 1-174.

    Type: COLOMBIA (Nouvelle Grenade). Dept. Nariño (Prov. de Barbacoas): Chutucal, 600 m, 1851–1857, Triana 4035 (holotype: BM-internet image!; isotypes: BR-internet image!, COL-internet image!, K-internet image!, NY!).

    Description: Shrub or small tree (1.2–)1.5–6(–7) m tall with branching from the upper nodes, bark green to brown-rusty. Upper internodes terete to compressed-rounded to rounded-quadrate 1.5–9 cm long, cauline nodes terete, nodal line present but faint and typically concealed by the dense indumentum. Indumentum on branchlets, petioles, blade bases of young leaves and primary veins adaxially, primary and secondary leaf veins abaxially, inflorescence axes, bracts and bracteoles abaxially, pedicels, hypanthia, calyx lobes, calyx teeth, and petals abaxially copiously to moderately covered with brownish dendritic trichomes 0.05–0.08 mm long with short axes and few-moderate number of terete arms. Leaves of each pair isophyllous; the semiterete petiole 1–4.5 cm long, canaliculate adaxially; blades (6–)8.5–34.5 × (2.2–)3.8–15 cm, elliptic to elliptic-ovate, the base broadly acute to obtuse, occasionally somewhat decurrent on petiole, the margin obscurely and distantly undulate-denticulate to denticulate, the apex acuminate, rarely caudate, chartaceous; mature leaves adaxially with surface and primary vein glabrescent, the secondary, tertiary and higher order veins glabrous; abaxial surface glabrous except for a few minute resinous short-stalked glands 0.015 mm long with thin-walled short heads, the secondary, tertiary and higher order veins sparsely beset with resinous glands of the same type and size; 5-plinerved, including the tenuous marginals, innermost pair of secondary veins diverging from the primary vein asymmetrically (occasionally symmetrically) 0.5–2 cm above the blade base, areolae 0.2–0.3 mm, adaxially the primary and secondary veins impressed, the tertiary and higher order veins flat, abaxially the primary and secondary veins elevated and terete, the tertiary and higher order veins slightly raised. Inflorescences a pseudolateral multiflorous dithyrsoid 4–10 cm long, including a compressed-rounded to rounded-quadrate peduncle 0.5–0.8 cm long, divaricately branched from the peduncle apex, borne in the upper leaf axils, the rachis green; bracts and bracteoles 0.4–0.7 × 0.3–0.5 mm, the bracts narrowly triangular to linear-oblong, the bracteoles triangular, green-brownish, glabrous adaxially, glabrescent abaxially, the bracts early deciduous, the bracteoles persistent in fruit. Flowers 5-merous, sessile or subsessile, pedicels 0.2–0.4 mm long when present. Hypanthia at anthesis 1.1–1.5 × 1.1–1.3 mm, free portion of hypanthium 0.8–1(–1.2) mm long, globose to suburceolate, bluntly 10-ribbed, green-whitish, ridged on the inner surface, sparsely beset with resinous glands as well as the torus adaxially. Calyx open in bud and persistent in fruit, light green; tube 0.2–0.3 mm long with the same vestiture as the torus adaxially and as the hypanthium abaxially; lobes 0.2–0.5 × 0.7–0.9 mm, depressed-rounded, the margin entire, the apex obtuse; exterior calyx teeth 0.1–0.3 mm long, minute, tuberculiform, somewhat perpendicular to the calyx lobes, inserted at the apical half of the lobes and typically not projecting beyond them. Petals 2–4.5 × 0.75–1 mm, lanceolate-triangular, the margin entire, the apex bluntly acute, white, glabrous adaxially, the indumentum abaxially present mainly apically and along the costa, spreading to reflexed at anthesis. Stamens 10; filaments 1.5–2 × 0.25 mm, white, drying yellow to light orange, glabrous; anther thecae 0.75–1.1 × 0.3–0.4 mm, oblong to oblong-obovate, emarginate at the apex, opening by two dorsally inclined pores 0.1–0.2 mm in diameter, pale yellow or white; connective pale yellow or white, its prolongation and appendage 0.4–0.75 mm long, the appendage oblong-lanceolate, bluntly acute at the apex, copiously gland-edged with short-stalked glands throughout the connective and its appendage. Ovary (4-)5-locular, 3/4 inferior, 0.65–0.85 mm long at anthesis, the apical collar absent, the apex 0.3–0.45 mm in diameter, conic, sparsely glandular-puberulent to glabrous; style 3.5–4 mm long, moderately tapered distally, white, glabrous; stigma expanded truncate to capitellate. Berries 2.5–3 × 3–4 mm when dry, globose-oblate, green and ripening white or green and changing to yellow, orange and ultimately purple when fully ripe, the hypanthial indumentum persistent at maturity. Seeds 0.26–0.36 × 0.13–0.21 mm, ovoid, angled, brownish; lateral and antiraphal symmetrical planes ovate, the highest point toward the chalazal side; raphal zone suboblong to sublinear, ca. 80% the length of the seed; appendage absent, but a small protuberance present; individual cells elongate, anticlinal boundaries channeled, undulate, with ?- and U-type patterns; periclinal walls convex, low-domed to nearly flat, microrelief verrucose. Chromosome number n=17.

    Common names: Ecuador: “chignul” used as pitchforks (Aulestia 1276, 1099, MO!, Quelal et al. 694, CAS!, Tipaz 1310, 1118, MO!); “mora” (Mexia 8428, CAS!).

    Habitat and Distribution: This species is common to occasional in primary and secondary rainforests, cloud forests, swamp forests, and disturbed sites, growing in the understory, in light gaps or near streams in flat areas, from Costa Rica throughout southern Central America south to Colombia, Ecuador, Perú, and with one record from western Brazil , at 5–2800(–3200) m. In Costa Rica it grows on the Caribbean slope along all the principal Cordilleras, to the Tortuguero plain, and south to the Golfo Dulce region on the Pacific slope. In Panama it is present throughout the country, both on the Pacific and Atlantic slopes. In Colombia it occurs on the Pacific slope of the Western Cordillera of the Andes, encompassing the Biogeographic Chocó Region, with fewer collections from the Central Cordillera. In Ecuador it is common throughout ranging south to Perú. In this study M. variabilis is reported for the first time in Brazil, where it occurs in the western region of Acre close to the Peruvian border. Manakins, Tanagers, Thrushes, the orange-billed Sparrow (Arremon aurantiirostris) and Myadestes melanops (in a Costa Rican premontane wet forest) have been reported to feed on M. variabilis berries (Stiles & Rosselli 1993). The White-ruffed Manakin (Corapipo altera) has also been reported to feed on M. variabilis fruits (Boyle 2006).

    Phenology: Collected in flower and fruit throughout the year.

    Etymology: The specific epithet refers to the variable colors of the mature fruits of this species.

    Taxonomy and Systematics: Miconia variabilis has a distinctive puberulent indumentum of dendritic trichomes on the petals abaxially, petiolate 5-plinerved leaves, 5-merous flowers, tuberculiform exterior calyx teeth that do not project, and oblong-obovate anthers that are emarginate at the apex. Miconia sessilis has similar vegetative and floral pubescence, and anther shape, but differs in having 4-merous flowers and leaf bases that are conspicuously decurrent on the petioles. The indumentum is also somewhat similar to that in M. bensparrei, M. incerta, and M. palenquensis, which collectively differ in their sessile, amplexicaul leaves. Miconia variabilis is the most basal species within the Variabilis subclade. This species is fairly consistent in indumentum and floral characters but the pubescence varies in quantity without any apparent correlation with elevation or other characters. The color of mature berries is highly variable in this species as well. There are at least two variants across its geographic and elevational range. The first variant has berries that are consistently white at maturity. These plants which are probably found throughout the species range are more abundant on the Atlantic slope of Costa Rica south to the Pacific slope in Panama (Bocas del Toro down to Darién) with populations also in Colombia, Ecuador and Perú, at 5–2800 m. It is difficult to delimit the exact geographic extent of this variant because collectors do not always record mature berry colors on specimens labels. The other variant includes individuals in which mature berries undergo a change of color through the maturation process. The fruits are initially green or green-white, then turning yellow, orange and in some cases red-purple. Berries with different colors can be seen on the same plant. The geographic distribution of this variant is clearer than the one with white berries. It occurs on the Pacific coast of Costa Rica (Parque Nacional Corcovado), south to Panama in the Atlantic province of San Blás to Darién. In Colombia, Ecuador and Perú this is the predominant variant, at 5–1325(–3200) m. From these distributions it appears that in Central America the two variants are clearly separated, but this is not clear in South America where both variants may be sympatric. The only record from Brazil was reported to have white berries at maturity. These two variants appear to represent divergent lineages within the same species. It would be of interest to learn whether the two berry color variants are selectively favored by the bird species that feed on them. There is one collection (Cuatrecasas 17033, F!, NY!, US!) that probably represents a rare variant from lowland Pacific Colombia (Valle), at 5–80 m. This specimen has smaller leaves than usual (mostly 6 × 2.2 cm), larger exterior calyx teeth (to 0.8 mm), and floral parts that are smaller overall than the norm. This collection is otherwise identical to M. variabilis in the puberulent indumentum and leaf venation, which are consistent diagnostic characters of this species. As discussed under M. laxivenula, the vegetatively glabrous population from eastern Ecuador described as Ossaea robusta f. glabrata Markgraf, will probably remain unknown until the “Pacapaca” region is more thoroughly explored (Wurdack 1973a).

    Conservation Status: This species would be considered Vulnerable VU B2ab(iii) according to IUCN criteria (AOO). However, because it occurs in many protected areas, a status of Least Concern LC is justified. It is protected in Brazil in the Serra do Divisor National Park (Acre). In Colombia it is protected in the Isla Gorgona National Park (Cauca); in La Planada Reserve (Nariño); and in in the Farallones National Park (Valle). In Costa Rica it is protected in the Volcán Irazú National Park (Cartago); in the Guanacaste National Park (Guanacaste); in La Selva Biological Station (Heredia); in the Braulio Carrillo National Park (Limón); in the Golfito Wild Life Reserve and in Corcovado National Park (Puntarenas). In Ecuador it is protected in the Awá Indigenous Reserve (Carchi and Esmeraldas); in the Sumaco-Napo-Galeras National Park and in the Jatún-Sacha Ecological Reserve (Napo); in ENDESA Forest Reserve (Pichincha); and in the Cuyabeno Scientific Station (Sucumbíos).

  • Sorry, no descriptions available for this record.