Miconia magnifolia Gamba & Almeda

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: COSTA RICA. Cocos Island, Hinds s.n. (holotype: K-internet image!).

Description: Subshrub to tree (1–)2–6(–12) m tall, moderately branched, bark brown-reddish. Upper internodes rounded-quadrate, 1.2–5 cm long, cauline nodes terete, bearing a well-defined nodal line forming a slightly deflexed flaplike outgrowth confluent with the abaxial bases of the petioles. Indumentum on branchlets, petioles, primary and secondary leaf veins abaxially, inflorescence axes, bracts, bracteoles, pedicels, hypanthia, calyx lobes and calyx teeth densely composed of brown matted subulate elongate smooth trichomes 0.4–0.7 mm long. Leaves of each pair isophyllous; the petiole 2.5–8 cm long, canaliculate adaxially, moderately grooved abaxially; blades 16–40(–50) × 9–18 cm, elliptic to oblong-elliptic, the base broadly acute, the margin subentire to denticulate, the apex bluntly short-acuminate, firm-chartaceous; adaxial surface of mature leaves, primary, secondary, tertiary and higher order veins glabrous; abaxial surface glabrous, the secondary, tertiary and higher order veins sparsely covered with caducous stellate lepidote trichomes 0.1–0.2 mm in diameter with only partially fused radii; 5-nerved, including the tenuous marginals, areolae 1–2 mm, adaxially the primary and secondary veins deeply impressed, the tertiary and higher order veins flat, abaxially the primary, secondary, tertiary and higher order veins prominently elevated and terete. Inflorescences a pseudolateral multiflorous dithyrsoid 4–12 cm long, including a rounded-quadrate peduncle 0.5–1(–3) cm long, divaricately and highly branched from the peduncle apex, borne in the upper foliar axils, the rachis green, the inflorescence nodes densely covered with the general tomentum but longer, each trichome up to 1 mm long; bracts 1–3 × 0.4–0.6 mm, oblong-lanceolate, concave, early deciduous at anthesis; bracteoles 1–3 × 0.7–1 mm, linear-oblong, concave, early to tardily deciduous in fruit. Flowers 5-merous on pedicels 0.25–0.5 mm long or subsessile. Hypanthia at anthesis 1.5–2 × 0.9–1.1 mm, free portion of hypanthium 0.9–1(–1.3) mm long, globose to urceolate, bluntly 10-ribbed, green-yellowish to reddish, ridged on the inner surface, smooth and minutely glandular, the glands sessile and somewhat translucent, the torus adaxially glandular-puberulent, the setae <0.3 mm long. Calyx open in bud and persistent in fruit, green; tube 0.15–0.3 mm long, with the same vestiture as the torus adaxially and the hypanthium abaxially; lobes 0.1–0.2 × 0.5–0.8 mm, minutely triangular, the margin vaguely undulate, the apex blunt; exterior calyx teeth 0.25–0.5 mm long, tuberculiform or obsolete, inserted at the base of the calyx lobes, equaling or slightly exceeding the lobes. Petals 2.5–4.6 × 1–1.9 mm, lanceolate or lanceolate-triangular, the margin entire, the apex bluntly acute, white to translucent white, drying orange, glabrous adaxially, abaxially with a thinly median line of matted elongate smooth trichomes <0.2 mm long, reflexed at anthesis. Stamens 10; filaments 1.5–2 × 0.25 mm, white to cream, glabrous; anther thecae 0.75–1 × 0.4 mm, oblong, obtuse to rounded at the apex, opening by one dorsally inclined pore 0.1 mm in diameter, white-yellowish; connective white-yellowish, its prolongation and appendage 0.75–0.85 mm long, the appendage oblong, obtuse to rounded at the apex, copiously and conspicuously gland-edged, the glands rounded and stalked, the stalks linear to subulate. Ovary typically 5-locular, occasionally 4-locular, 1/2 to 2/3 inferior, 1.1–1.5 mm long at anthesis, the apical collar 0.5–0.8(–1) × 0.2–0.3 mm, conic-truncate, sparsely to moderately glandular-puberulent; style (2.5–)3.5–4.5 mm long, moderately narrowed distally (i.e. tapering), white, glabrous; stigma capitellate to capitate. Berries 4–6 × 4–6 mm when dry, globose-oblate, yellow-orange then pink-red to red-purple when fully ripe, the hypanthial indumentum persistent at maturity. Seeds 0.31–0.43 × 0.12–0.18 mm, typically pyramidal, occasionally ovoid and angled, brownish; lateral and antiraphal symmetrical planes triangular, 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 U-type patterns; periclinal walls convex, low-domed to nearly flat, microrelief verrucose.

Common names: Colombia: “sietecueros” (Guaviare); “cenicero” (Chocó) (Bernal et al. 2011).

Habitat and Distribution: Occasional in primary or secondary rainforests and disturbed sites. It commonly grows in swampy areas and light gaps, from southern Nicaragua through southern Central America, to Colombia and Ecuador , at 0–1400(–1800) m. In Costa Rica it occurs throughout its territory, including Cocos Island down to Isla de Coiba, south to the Atlantic slope of Panama. In Colombia it is known from the lowland Pacific slopes and premontane forested slopes of the Andes to Isla Gorgona in the Pacific Ocean, south to the Andean forested slopes in Ecuador. White-ruffed Manakins (Corapipo altera) have been reported to feed on M. magnifolia fruits in a wet forest of northeastern Costa Rica (Boyle 2010). Manakins, Tanagers, Thrushes, the orange-billed Sparrow (Arremon aurantiirostris) and Myadestes melanops have been reported to feed on M. magnifolia berries in a Costa Rican premontane wet forest (Stiles & Rosselli 1993). Other fruit-eating birds of the tropical forest understory (at Estación Biológica La Selva, Costa Rica) that have been reported to consume M. magnifolia fruits include Chlorothraupis carmioli, Corapipo leucorrhoa, Euphonia gouldi, Hylocichla mustelina, Mionectes oleaginous, and Pipra mentalis (Loiselle & Blake 1999, 2000). The tawny-crested Tanager, Tachyphonus delatrii was also observed to feed on mature berries of M. magnifolia in Costa Rica (Solano 3505, NY!).

Phenology: Collected in flower and fruit throughout the year.

Etymology: The specific epithet refers to the large leaves of this species.

Taxonomy and Systematics: The combination of large leaves, tomentose indumentum on vegetative and floral parts, and conspicuous leaf reticulation makes M. magnifolia readily recognizable among species of the Octopleura clade. This species has copious stalked glands on the long (0.75–0.85 mm) staminal connective appendage and prolongation, a toral corona that is densely glandular adaxially, and an apical ovary collar that is densely glandular-puberulent. Wurdack (1973a) noted that the matted indumentum on the petals is rather sparse in Central American and Pacific Colombian slope individuals, but moderately dense in collections from the the rest of Colombia and Ecuador. It is most closely related to M. bractiflora, M. formicaria, M. rufibarbis, and M. spiciformis with a basal position among this group of species , which share a tomentose hypanthial indumentum and similar seeds. Miconia magnifolia most resembles M. bractiflora in foliage details, especially the tertiary/intertertiary vein reticulation but the latter lacks the tomentose-matted caducous cauline pubescence and has broader bracts, thicker hypanthial pubescence, and shorter stamen connectives that are barely (0.1 mm) prolonged (Wurdack 1973a).

Conservation Status: Considered Vulnerable VU B2ab(iii) following IUCN criteria (AOO). However, a status of Least Concern is justified based on the fact that it is protected in many areas. Protected in Colombia in Las Orquídeas National Park (Antioquia); in the Gorgona National Park (Cauca); and in the Amargal Biological Station (Chocó). In Costa Rica it is protected throughout its territory in different National Parks and Reserves. In Ecuador it is protected in the Awá Indigenous Reserve (Carchi and Esmeraldas, and in the Cotocachi-Cayapas Ecological Reserve (Esmeraldas); in the Yachana Reserve and in the Jatún-Sacha Biological Station (Napo); in the ENDESA Forest Reserve (Pichincha). In Nicaragua it is protected in the Indio-Maíz Reserve (Atlántico Sur and Río San Juan). In Panama it is only protected in the Darién National Park.

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