Miconia quadridomius Gamba & Almeda 2014, nom. nov.
Creators: name: Gamba, Diana
name: Almeda, Frank
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Melastomataceae
Miconia
Miconia quadridomius

description: 24. Miconia quadridomius Gamba & Almeda, nom. nov. Basionym: Clidemia cuatrecasasii Wurdack (1981: 248–249). Type: COLOMBIA. Dept. Valle: Puerto Merizalde, costa del pacífico, Río Naya, 5–20 m, 20–23 February 1943, Cuatrecasas 13957 (holotype: US!). Nec Miconia cuatrecasae Markgraf in Cuatrecasas (1933: 27).   
 Openly branched shrub or small tree (1.5–) 2–6 m tall. Upper internodes rounded-quadrate, (2.1–) 3.2–4.9 cm long, cauline nodes terete, nodal line absent. Indumentum on branchlets, petioles, surface of young leaves, primary and secondary veins adaxially, primary and secondary leaf veins abaxially, bracts apically, pedicels, hypanthia, calyx lobes abaxially, and exterior calyx teeth densely to copiously composed of ferruginous elongate slightly or moderately roughened trichomes 2–3 mm long, each trichome deflexed and somewhat flattened, densely intermixed with an understory of clavate dendritic trichomes 0.1–0.3 mm long with short to moderately long thinwalled (flattened) arms. Leaves of each pair slightly to commonly anisophyllous in size; the semiterete short petioles 0.8–1.5 mm long, superficially canaliculate adaxially; larger blades 18–27 × 6.7–10.2 cm, smaller blades 7–16 × 2.5–6.5 cm, elliptic to elliptic-obovate, the base typically rounded, frequently becoming attenuate but ending in a rounded-cordate base, the margin serrulate to crenulate, the apex acuminate to caudate-acuminate, chartaceous; mature leaves adaxially with both the dendritic and elongate trichomes on the surface, primary and secondary veins becoming sparse to caducous with age, the tertiary and higher order veins glabrescent; abaxial surface glabrous, the tertiary and higher order veins sparsely and caducously covered with the general dendritic trichomes; 5-(7-)plinerved, including the tenuous marginals, innermost pair of secondary veins diverging from the primary vein 0.3–2 cm above the base, forming a deeply tufted cavity beset with the general indumentum (acarodomatia?), areolae 0.3–0.4 mm, reticulation visible on both surfaces, adaxially the primary and secondary veins slightly impressed, the tertiary and higher order veins flat, abaxially the primary and secondary veins elevated and terete, the tertiary and higher order veins slightly elevated. Inflorescences a congested axillary fasciculate glomerule 1–1.5 cm long, sessile, unbranched, typically paired and seemingly cauliflorous on defoliated nodes; bracts 1.5–7 × 0.4–0.6 mm, subulate, thin, erect, with inconspicuous parallel venation, glabrous on the main surfaces but the general elongate roughened indumentum present at the apex, each bract seemingly branched, persistent to tardily deciduous in fruit. Flowers 4-merous on thick pedicels 0.4–1 mm long. Hypanthia at anthesis 2.7–3 × 0.9–1 mm, free portion of hypanthium 1.3–1.7 mm long, tubular to suburceolate, bluntly 8-ribbed, ridged on the inner surface, moderately scaly, the torus adaxially copiously beset with short-stalked glands with thinwalled short heads. Calyx open in bud and persistent in fruit; tube 0.1–0.3 mm long, adaxially with the same type of glands as the torus, abaxially with the same vestiture as the hypanthium; lobes 1.5–2 × 0.8–1.1 mm, ovate-oblong,   
 108 Phytotaxa 179 (1) © 2014 Magnolia Press   
GAMBA & ALMEDA  
 the margin entire, the apex retuse to obtuse, the adaxial surface glabrous or minutely resinous-puberulent, reflexed at anthesis; exterior calyx teeth 1–1.5 mm long, subulate, inserted at the base of the calyx lobes and barely spreading beyond them. Petals 1.5–3.5 × 0.6–1 mm, oblong to linear-oblong, the margin entire, the apex roundedobtuse, white, glabrous on both surfaces, reflexed at anthesis. Stamens 8; filaments 1.4–1.5 × ca. 0.2 mm, white, glabrous; anther thecae 1.3–1.5 × 0.23–0.36 mm, linear-oblong and slightly clavate, somewhat emarginate at the apex, opening by one dorsally inclined pore 0.1 mm; connective darker than the thecae, its prolongation and appendage 0.2–0.3(–0.5) mm long, the appendage lanceolate, bluntly acute at the apex, copiously gland-edged, the glands rounded and conspicuously stalked to 0.2 mm long. Ovary 4-locular, 3/4 to completely inferior, 1.3–1.45 mm long at anthesis, the apical collar 0.3–0.4 × 0.55–0.65 mm, conic, copiously glandular-ciliate; style 5–7 mm long, parallel-sided (i.e. terete), white, glabrous; stigma truncate to capitellate when dry. Berries 2–2.5 × 2 mm when dry, globose and slightly oblate, bright orange when ripe, the hypanthium indumentum persistent in fruit. Seeds 0.68–0.79 × 0.5–0.65 mm, pyramidal, brown; lateral symmetrical plane triangular, the highest point near the central part of the seed; antiraphal symmetrical plane suboblong; raphal zone circular to suboblong, ca. 40% the length of the seed; multicellular sculpture rugose throughout the seed; individual cells elongate, anticlinal boundaries channeled, irregularly curved; periclinal walls convex, low-domed to nearly flat, microrelief striate.   
 Additional specimens studied:— COLOMBIA. Chocó: Vía de Morro de Mico al “Mirador” por el camino hacia “Jurubidá” en dirección Sy posteriormente hacia “Copete de Pava” en dirección N, 6°5’N, 77°10’W, 0–100 m, 15 May 1990, Barbosa 6598 (MO, US); P.N. de Utría, Serranía ubicada al NE de la Ensenada de Utría por la trocha llamada del M-19, 6°20’N, 77°20’W, 0–100 m, 12 June 1990, García-Cossio & Agualimpia 500 (CHOCO, MO); Hoya del Río San Juan, Quebrada Taparal, afluente del Río San Juan, 4°12’N, 77°8’W, 5–10 m, 28 March 1979, Forero et al. 4247 (COL, MO). Valle: (Buenaventura), Along road between Buenaventura and Málaga vicinity of Bajo Calima, km 3.5.2 from main Cali-Buenaventura Hwy, at Gallinero, 4°0’N, 77°3’W, 100 m, 15 July 1993, Croat & Bay 75749 (MO); (Buenaventura), Bajo Calima, Ca, 15 km Nof Buenaventura, Cartón de Colombia concession, Dindo area, 3°59’N, 77°2’W, 50 m, 26 March 1986, Gentry et al. 53646 (MO, US); (Buenaventura), Bajo Calima, ca. 10 km due Nof Buenaventura, Cartón de Colombia concession, 3°56’N, 77°8’W, ca. 50 m, 5 December 1981, Gentry 35354 (CAS, MO); (Buenaventura), Bajo Calima, ca. 15 km Nof Buenventura, Cartón de Colombia concession, 3°56’N, 77°8’W, ca. 50 m, 18 February 1983, Gentry & Juncosa 40492 (MO); (Buenaventura), Bajo Calima, Granja Agroforestal, 40 m, 29 March 1984, Devia 491 (MO, TULV); (Buenaventura), Bajo Calima, Estación Agroforestal, Secretaría de Agricultura y fomento, Parte NE del campamento, 40–60 m, 5 August 1979, Cabrera 5181 (CUVC, MO); (Buenaventura), San Isidro, Bosque INDERENA-CONIF, 40 m, 5 March 1989, Devia & Prado 2641 (CAS, TULV); (Cordoba), Dagua Valley, 80–100 m, 6 May 1922, Killip 5119 (US); La Trojita, Río Calima (región del Chocó), 5–50 m, 19 February 1944, Cuatrecasas 16623 (US). ECUADOR. Esmeraldas: Road Lita-Alto Tambo-San Lorenzo, km 6.9 from Lita, 0°52’24.6"N, 78°29’33.2"W, 720 m, 30 September 2001, Cotton et al. 1794 (CAS, QCA). PANAMA. Comarca de San Blás: Headwaters of Río Nergala along continental divide, 350 m, 11 January 1985, de Nevers & Herrera 4515 (CAS, MO); Llano-Cartí Road, km 16, trail to creek on Atlantic drainage, 250–350 m, 2 February 1989, Almeda et al. 6522 (CAS, MO, NY, PMA); Nusagandi, Along continental divide on El Llano-Carti road, Headwaters of Atlantic draining creeks, 9°19’N, 78°15’W, 320 m, 12 August 1984, de Nevers & Pérez 3694 (CAS). Panamá: Along El Llano Carti-Tupile road, 12 mi above Pan-Am Hwy, 200–500 m, 26 March 1973, Liesner 1135 (CAS, NY).   
 Illustration:— None found.   
 Common names and documented uses:— None recorded.   
 Habitat, distribution and ecology:— Local and uncommon in understories of rain forests, typically in deep shade and/or along streams in Panama, Colombia and Ecuador (Fig. 16), at 0–720 m. It is most common in the Bajo Calima region (part of the Chocó) in the department of Valle in Colombia. It was recently reported from Panama (Almeda 2009). Specimens from Ecuador that were previously attributed to this species are M. chocoensis.   
 Phenology:— Collected in flower from January through March and from May through August; in fruit from February through March, June through September, and in December.   
 Etymology:— The specific epithet honors José Cuatrecasas (1903–1996), Spanish botanist and prolific collector of Colombian plants.   
 Discussion:— This distinctive species has an indumentum of elongate-roughened trichomes on vegetative and hypanthial parts, conspicuous 5-plinerved leaves and a poorly developed-sessile inflorescence. Almeda (2009)   
 SYSTEMATICS OF THE OCTOPLEURA CLADE OF MICONIA   
 Phytotaxa 179 (1) © 2014 Magnolia Press 109 noted that the Panamanian populations differ from those in Colombia by the presence of shorter bracts to 2 mm long (vs. 6–7 mm long) calyx lobes adaxially glabrous (vs. resinous-puberulent); we agree with these observations. In all other characters, the material from both countries is similar in foliar shape, indumentum details, and staminal and seed morphology.   
 In M. quadridomius the leaves are plinerved, but there is a space formed in between the innermost pair of secondary veins and the primary vein before the point of divergence. This space may serve to house insects. Althought some ants were found in this leaf area among different specimens from the Bajo Calima region (Colombia), the morphology of this structure is not a usual ant-domatium. It is more similar to an acarodomatium; further natural history studies are required in order to elucidate the function of this structure. This species is similar to M. chocoensis, but differs in the foliar plinervation and in lacking white furrowed glands on the leaves abaxially. In M. quadridomius the vegetative and hypanthial indumentum is ferrugineous (vs. white), and consists of prominently roughened flattened-deflexed trichomes (vs. slightly roughened). Miconia quadridomius is also similar to M. approximata, which has vegetative pubescence that is shorter (0.3–0.7 mm long vs. 2–3 mm long), and the abaxial tertiary and higher order foliar veins densely resinous-glandular (vs. furfuraceous). In the protologue, Wurdack (1981) provides a detailed enumeration of the differences between these species.   
 Conservation status:— Endangered EN B2ab(iii). Protected only in Colombia in the Ensenada de Utría National Park (Chocó); the threats include destruction of its natural habitat and the fact that it is not protected in other parts of its range.
description: Published as part of Gamba, Diana & Almeda, Frank, 2014, Systematics of the Octopleura Clade of Miconia (Melastomataceae: Miconieae) in Tropical America, pp. 1-174 in Phytotaxa 179 (1) on pages 108-110, DOI: 10.11646/phytotaxa.179.1.1, http://zenodo.org/record/10089927