Miconia dulcis Jan.M.Burke, Michelang. and K.Grant, 2018

Burke, Janelle M. & Michelangeli, Fabian A., 2018, Six new species of Miconia (Miconieae, Melastomataceae) from the Andes, Phytotaxa 361 (2), pp. 131-150 : 141-145

Miconia dulcis Jan.M.Burke, Michelang. and K.Grant , sp. nov. ( Fig. 6 )

Diagnosis: Similar to other species of Miconia section Chaenopleura with 4 petals, paired, brown glands at base of petiole, and galeate stigma, but distinguished by stems with distinctly swollen nodes, nodding flowers, and setose indumentum on petioles and abaxial leaf surfaces, comprised of uncinate trichomes.

Type:— BOLIVIA: Cochabamba. Prov. Carrasco, 6 km al SE de Siberia por el camino entre Cochabamba y Santa ruz (23 km en linea recta al NE de Camarapa ), 2850 m, 17˚50´ S, 64˚44´ W, 10 February 1987 (fl), J. C. Solomon 16013 & M. Nee (holotype: NY!; isotypes: MO!, US!) .

Shrub, up to 4 m tall. Young stems terete, the indumentum with sparse dendritic, uncinate, setose hairs (0.5 mm long), internodes with faint longitudinal ridges, nodal line absent, nodes conspicuously swollen. Leaves and swollen nodes with beige, paired, ovoid, glands at base of petiole; the petiole 0.8–1.7 cm long, the indumentum setose, brown, uncinate trichomes (0.5–0.6 mm long); the blade 3.4–4.5 × 1.4–2.1 cm, lanceolate to elliptical, chartaceous, the apex acute to acuminate, the base attenuate, the margin finely serrulate to ciliate; secondary veins 2 including the faint marginals, tertiary veins not prominent, basally nerved, symmetrical, tertiary veins percurrent, reticulate, areoles 1 mm wide, veins slightly impressed abaxially on the adaxial surface and slightly raised adaxially on the abaxial surface, brown to tan; adaxial surface dark green, the surface subglabrate, and translucent, with sessile glands on the primary and secondary veins; abaxial surface light green to yellow, the surface glabrous, translucent, with sessile glands; mite domatia present as tufts of hairs in axils of abaxial veins. Inflorescences terminal, panicles of cymose units (=polychasial cymes), 4.4–8.1 cm long; peduncles terete, brown, the indumentum densely pubescent with simple, uncinate hairs, ca. 0.5 mm long; bracts and bracteoles not seen. Flowers 4-merous, bisexual; the pedicel 0.5–0.75 mm long. Hypanthium 1.85–3.3 mm long, broadly campanulate, 2.3–4 mm wide at the torus, external indumentum sparse sessile, translucent glands, internal surface glabrous, androecial fringe absent. Calyx open in bud, the tube 0.3 mm long at anthesis, the lobes vestigal, 0.4–0.6 × 0.5–1.0 mm, glabrous, green to tan; calyx teeth 0.3–0.5 × 0.5–1.6 mm, deltoid, glabrous, tan to pink, with central gland. Petals 0.9–2 × 1.4–2.9 mm, ovate to orbicular, erect, white to beige at anthesis (drying beige to yellow), glabrescent with transluscent, sessile glands with brown apex, the apex entire or retuse, the base blunt, the margin entire to erose in apical portion, moderately granulous. Stamens diplostemenous, isomorphic, erect at anthesis; the filaments 1.1–2.5 mm long, puberlant with glandular hairs, white to beige, anthers with 2 locules, thecae 1.8–2.3 × 0.9–1.5 mm, squat to quadrangular, opening by 2 truncate 0.3 mm pores, pale yellow at anthesis, later turning brown, septum prolonged above thecae 0.3–0.4 mm, brown, glabrous. Ovary 4-locular, 1/3 free, the free portion projecting 0.5–0.7 × 1.2–1.5 mm, conical with ridges, glabrous, the apex without a corona; style 1.1–4.5 mm long, straight, brown, puberulant with elongated, roughened hairs; stigma galeiform, 0.9–1.2 × 1.2–1.4 mm wide. Berries 2.5–3.6 × 3.1–3.9 mm, spherical, dark green, indumentum present when mature. Seeds immature, 0.4 mm long, pear shaped, the raphal zone covering 20 % of the seed. Chromosome number not known.

Distribution.— Cloud forest, 2850–3300 m in the province Cochabamba, La Paz and Santa Cruz, Bolivia (Fig. 3).

Phenology.— Flowering in February–April. Fruiting year round.

Etymology.— The epithet refers the sweet smell of the flowers, as noted on collection labels.

Conservation Assessment.— Miconia dulcis is known from one area on the border between the Provinces of Santa Cruz and Cochabamba in dwarf forests, along the road from Comarapa to Cochabamba. The extent of occurrence is only 6.5 km 2 (8 data points). Thus, we recommend that this species is categorized as critically endangered, CR B1ab(i) ( IUCN 2001).

Additional specimens examined: BOLIVIA: Cochabamba: Prov. Carrasco: 3.5 km del pueblo de Siberia , 2950 m, 17˚50’ S, 64˚44’ W, 5 March 1988 (fl), Saldias 278 (US) ; ‘ Siberia’, km 220 and 222 on the Cochabamba-Santa Cruz hwy, between Pojo and Comarapa, 2800 m, 17 ˚50’ S, 64˚40’ W, 20 April 1963 (fr), D. & V. Ugent 510 7 ( US) ; Siberia, 2969 m, 17˚50’12˝ S, 64˚44’04˝ W, 19 February 2005 (fl), Altamirano 646 & Teran ( MO) ; Siberia, 2940 m, 17˚49’47˝ S, 64˚ 44’07˝ W, 20 February 2005 (fl), Fernandez 3234 & Altamirano ( MO) ; Com. Lach’ujmayo , 3300 m, 22 November 1990 (fr), Hensen 928 ( US) ; Siberia. pendiente de 30 deg de inclinacion, 2969 m, 17˚50’12 ˝S, 64˚ 44’ 04˝W, 20 February 2005 (fr), Teran & Altamirano 250 ( US). Santa Cruz: Prov. Caballero, Entre el Empalme y Locotal, 2100–2850 m, 17°50’ 38”S, 64°41’ 34”W, 10 April 2004 (fl), Calzadilla 151 et al. ( NY) ; 7.3 km (by road) E of Siberia, 3.8 km (by road) NW of El Empalme, along highway from Cochabamba to Comarapa , 2750 m, 17°50’04”S, 64°42’55”W, 5 May 2007 (fr), Nee et al. 55366 ( LPB, NY, USZ) .

Miconia dulcis is likely closely related to Miconia latifolia Naudin (1850:244) , another Andean Miconia species with 4-merous flowers. They share the paired glands at the base of the petiole, though these are brown in M. dulcis and often white in M. latifolia . The stigma of M. dulcis is much larger; the stigma in M. latifolia is capitate instead of galeate. In addition, M. latifolia often has stems and inflorescence axes that are quadrangular to flattened in cross section. In M. dulcis , the tertiary veins are not prominent, as in M. flavescens Cogniaux (1890:93) , another Bolivian Miconia species with 4-merous flowers and capitate stigmas. Miconia griffisii MacBride (1929:188) is another species in the Miconia latifolia complex, though the indumentum is setulose-hirtellous and the paired glands at the base of the petiole are white, not brown.

Figures

FIGURE 6. Miconia dulcis A. Habit. B. Vegetative node, showing paired ovoid glands at base of petiole. C. Protogynous flower with galeate stigma. D. Flower at anthesis. E. Longitudinal section of flower with detail of ridged apex of ovary. F. Outer (upper) and inner (lower) calyx teeth and lobes. G. Petal. H. Stamens from left to right: dorsal, ventral and side view. I. Habit of plant in fruit.J. Fruit (berry). Drawn from Solomon 16013, NY and Nee 55366, NY.