Miconia cernuiflora Jan.M.Burke & Michelang., 2018

Burke, Janelle M. & Michelangeli, Fabian A., 2018, Six new species of Miconia (Miconieae, Melastomataceae) from the Andes, Phytotaxa 361 (2), pp. 131-150 : 132-138

Miconia cernuiflora Jan.M.Burke & Michelang. , sp. nov. ( Fig. 1 , 2 )

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 elliptical-oblong leaves and beige indumentum on veins of abaxial surface of leaf blades.

Type:— BOLIVIA. La Paz: Prov. Sud Yungas, 1.4 km W of Unduavi, on new road between Chuspipata and La Paz, 3400 m, 16˚18´ S, 67˚55´ W, 2 July 1986 (fl), J. C. Solomon 15381 (holotype: NY!; isotypes: MO!, US!) .

Treelet, up to 5 m. Young stems terete, the indumentum of dendritic hairs, long axis, roughened, some with short arms at apex, 0.5–1 mm long, internodes without longitudinal ridges, nodal line absent. Leaves isophyllous; petiole 0.9–2.1 cm long, the indumentum with beige dendritic hairs, ca. 0.5 mm long, the base with paired ovoid glands, drying beige; the blade 7.0–11.0 × 1.9–3.3 cm, oblong-elliptical, subcoriaceous, the apex abruptly acuminate, 2–6 mm, the base obtuse to round, the margin revolute, serrate, teeth ca 0.5 mm; secondary veins 4 including faint marginal pairs, basally nerved, faint marginal veins present, tertiary veins percurrent, diverging at 45–70° angle from primary vein, reticulate, veins slightly impressed on the adaxial surface and raised on the abaxial surface; adaxial surface dark green, glabrous, but with translucent sessile glands on the primary and secondary veins; abaxial surface green drying brown, the indumentum on the surface with sparse dendritic hairs, veins covered with beige dendritic hairs with elongate axis and short terete arms. Inflorescence a terminal, few-branched panicle of dichasial units (thyrsiform), 5.8–11.2 cm long; peduncles terete, green with brown pubescence, the indumentum densely rufose with same hairs as stem, flowers nodding; the bracts 4 × 1.4 cm, lanceolate to subulate, caducous; bracteoles 1.2 × 0.5 cm, oblong, caducous, margin ciliate with dendritic hairs. Flowers 4-merous, bisexual; the pedicel 0.6–1 mm long, same pubescence as inflorescence axis. Hypanthium 2.3–2.6 mm long, semi-hemispherical, 3.2–3.7 mm wide at the torus, external indumentum with few sessile, translucent glands, internal surface glabrous, androecial fringe absent. Calyx open in bud, the tube 0.2 mm long at anthesis, the lobes 0.5 × 0.5 mm, bluntly deltoid, glabrous, hyaline; calyx teeth vestigial and swollen, glabrous. Petals 1.2–1.5 × 2–2.2 mm, orbicular, spreading, white at anthesis (drying yellow), densely granulose on abaxial surface, the apex mostly retuse, the base slightly attenuate, the margin entire to erose. Stamens diplostemenous, isomorphic, radially spreading at anthesis; stamen filament 1.4–2.3 mm long, with few sessile pigmented glands, stipitate glands towards apex, white, the anthers with 2 locules, thecae 1.6–1.7 × 0.7–1.1 mm, obovate, opening by 2 truncate pores, septum protruding 0.5–0.8 mm, pores 0.4–0.6 mm wide, pale yellow at anthesis, later turning brown, the connective prolonged below thecae 0.5 mm, with small dorsal bump, pale yellow, glabrous. Ovary 4-locular, 1/3 inferior, the free portion projecting 0.5 x 1.7 mm, conical, with stipitate glands, corona absent; style 2 mm long, erect, white, puberulent; stigma galeate, 1.5 × 1.5 mm. Berries and seeds not seen. Chromosome number not known.

FIGURE 3. Distribution map of Miconia cernuiflora ■, Miconia cinnabarina ○, Miconia dimorphotheca ∆, and Miconia dulcis ●, in Southern Peru and Northern Bolivia.

Distribution.— Humid montane forest, 3400–3800 m, Bolivia (Cochabamba, La Paz) and Peru (Cusco). (Fig. 3). Phenology.— Flowering in April–July.

Etymology.— The epithet refers the nodding flowers at anthesis.

Conservation assessment.— Miconia cernuiflora is distributed in cloud forests from Cusco, Peru to Cochabamba, Bolivia, with an extent of occurrence (EOO) of over 50,000 km 2 (calculated from 10 data points). In spite of its relatively broad distribution, fewer than 20 collections are known. At this time we provisionally designate this species as Least Concern ( IUCN 2001), though it should be revaluated if found currently known populations are in decline or extinct.

Additional specimens examined: BOLIVIA: La Paz: Prov. Nor Yungas , Rio Coscapa trail, following the trail to the Rio Coscapa from its inception on the Yungas hwy ca. 3 km NE of Unduavi to the ridge line, 3420–3480 m, 16˚17’ S, 67˚54’ W, 30 April 1988 (fl), Lewis 88329 ( MO, NY) ; Cochabamba to Chapare , 3800 m, 6 April [without year], Cardenas 5970 ( US) ; Prov. Nor Yungas , Unduavi, 3300 m, November 1910 (fr), Buchtien 2911 ( BR, F, US) ; Prov. Sud Yungas , Cant’on Lambate, Chillkani, 3400 m, 16˚35’ S 67˚44 ’ W, 12 May 1994 (bud) Pizarro 8 ( MO) ; Prov. Franz Tamayo , Senda Pelechuco-Mojo , sector Tambo Qumado, a los alred. del compamento principal sobre la senda Pelechucho-Mojos, 3577 m, 14˚41’ 32˝S, 68˚58’ 48˝W, 8 May 2003 (fl), Bascope 433 & Jorgensen ( MO) ; Prov. Sud Yungas , 3 km E of Unduavi, on road between La Paz and Chuspipata, 3300–3400 m, 16˚17’ S, 67˚53’ W, 2 July 1986 (fl), Solomon 15428 ( MO, US). Cochabamba: Prov. Jose Carrasco Torrico, 98 km carretera antigua Cochabamba- Villa Tunari, 3400 m, 17˚12’ S, 65˚42’ W, 27 June 1996 (fl), Kessler 6744 et al. ( MO) ; Prov. Chapare , ca. 8 km N Maycamayu , ca. 70 km from Sacaba , 17˚12’ S, 65˚57’ W, 12 August 1991 (fl), Kessler 2903 ( MO). PERU: Cusco: Prov. Paucartambo, bajanco Acjanacu, km 102, 3550 m (bud), 3 June 1964, Vargas C. 15479 (US) ; Dto. Challabamba. Carretera Paucartambo-Pillcopata. 1 km N de la entrada del Parque Nacional Manu, 3493 m, 14 June 2012 (fl), Michelangeli 1890 ( NY, USM) .

This species would be classified in Miconia section Chaenopleura as circumscribed by Cogniaux (1891), due to the 4-merous flowers and broad anther pores. Miconia cernuiflora is closely related to Miconia mandonii Cogniaux (1891:911) , another species in Miconia section Chaenopleura . Both species share 4-merous flowers, galeate stigmas, and anthers opening with broad pores. Miconia cernuiflora has beige to tan trichomes, that densely cover the stem and inflorescence axis. Miconia mandonii pubescence is deep red, including the veins, and the pubescence on the abaxial leaf surface is largely confined to the mid-rib, whereas in M. cernuiflora it is along all secondary veins. Miconia mandonii has dark brown stems, smaller leaves (5–8 cm), sparser pubescence, and pink petals. Miconia cernuiflora has dense, rufous pubescence, longer leaves, and white petals. Some specimens studied for this project appear to be intermediate between the two species in both leaf blade pubescence and coloration, Lewis 39974 ( US), Lewis 38925 ( US), and Lewis 39351 ( US), and were not included in the species circumscription of M. cernuiflora . These specimens are all from Inquisivi Province, Peru and have 4 or 5-merous flowers. These specimens have pink venation and leaves that are like Miconia mandonii in size and shape. Both species are often locally abundant where they occur.

Figures

FIGURE 1. Miconia cernuiflora. A. Habit. B. Detail of inflorescence C. Protogynous flower. D. Flower at anthesis, with exerted stamens. E. Petal F. Longitudinal section of flower at anthesis. G. Stamens, from L to R: dorsal, ventral and side view. Drawn from Solomon 15381, NY and Michelangeli 1890, NY.

FIGURE 2. Miconia cernuiflora. A. Inflorescence. B. Flower, top view. C.. Flowers, lateral view. D. Detail of branch and petiole, showing paired glands. E. Leaf, abaxial surface. (all photos by F.A. Michelangeli from Michelangeli 1890)