Miconia yanachagaensis Michelang. & R.Goldenb., 2018

Michelangeli, Fabián A. & Goldenberg, Renato, 2018, New and noteworthy Melastomataceae from the Yanachaga-Chemillén National Park and surrounding areas in Oxapampa, Pasco, Peru, Phytotaxa 374 (3), pp. 185-210 : 196-199

4. Miconia yanachagaensis Michelang. & R.Goldenb. sp. nov. ( Figures 7–8 )

Diagnosis:—Differs from Miconia incachacana Wurdack (1972: 483) due to the flattened to terete branches (vs. obviously tetragonal in M. incachacana ), smaller leaves (7–13 × 4–6 cm vs. 10–22 × 4.5–7.5 cm), shorter inflorescence (6–16 cm long vs. 14–23 cm long), larger petals (6.3–7.1 × 5.5–6.5 mm vs. 4.8–5 × 4–4.2 mm), and glabrous ovary apex (vs. with a glandular-ciliolate collar).

Type:— PERU. Pasco: Province of Oxapampa, Dist. Huancabamba, Parque Nacional Yanachaga-Chemillén, parte alta de la trocha Yanachaga-Palcazú , 2650 m, 10°22’42”S 75°27’00”W, 1 December 2007 (fl), A. Monteagudo 16057 (holotype: USM!; isotypes: HOXA!, MO!, NY!) .

Shrubs or treelets 1.5–4(–7) m tall, occasionally decumbent. Young stems terete to slightly flattened and depressed at the internode apices, and terete with age, interpetiolar/subpetiolar ridge very thick and continuous, i.e. there is an annular structure around the stem node, the young stems densely covered with long dendritic-pedicellate trichomes, 0.4–1.5 mm long, erect, eglandular, the axis rough at the base then simple or with very short arms concentrated at its apex, ochraceous, the trichomes paler and somewhat caducous on older stems. Leaves opposite, isophyllous; petiole 9–12 mm long, with the same trichomes as the stems; blade 7–13 × 4–6 cm, obovate to elliptic, apex obtuse to broadly acute, base acute or rounded, margin repand, hyaline and revolute, coriaceous, acrodromous nerves 5, suprabasal (the inner pair of secondaries joining the midvein 4.5–9(–13) mm above the base), the outer pair submarginal, distally fainter and disappearing towards the leaf apex, tertiary complete vein pairs 22–28, lacking intercalating, incomplete, percurrent veins, midvein and secondary veins strongly impressed, tertiary veins and reticulation slightly impressed on the adaxial surface, midvein, secondary and tertiary veins strongly prominent, and reticulation prominent on the abaxial surface, adaxial surface moderately to sparsely covered with dendritic trichomes in young leaves, and caducous or broken in older ones, sometimes persistent along the main nerves, abaxial surface moderately to densely covered (but never completely concealing the surface) with dendritic-penicellate trichomes 1–2 mm long, erect but curved, the axis rough and with very short arms concentrated at the somewhat widened apex, eglandular, brownish. Panicles 6–16 × 3–6.5 cm long, terminal, broadly pyramidal, multiflorous, with 3 main axes departing from the base, each one with 4–6 pairs of erect paraclades, nodes lacking accessory branches, the axis covered with the same indumentum as the branches; bracts and bracteoles not seen, and probably very early caducous. Flowers on short pedicels 1–1.5 mm long, 5-merous. Hypanthium ca. 3.5–4 × 4.5–5 mm, campanulate, green, outside densely covered with dendritic trichomes similar to the ones on young stems and inflorescences, inside glabrous; torus glabrous. Calyx tube 1.1–1.4 mm long; sepals internal laminae 2.3–2.6 mm long, reddish, trapezoidal, the apex truncate, margins lacerate-ciliolate; sepals external projections a mere triangular hump, shorter than the laminae. Petals 6.3–7.1 × 5.5–6.5 mm, broadly obovate, apex slightly emarginate and asymmetrical, margin entire, glabrous, white. Stamens isomorphic, yellow; filaments 4.5–4.8 mm long, moderately covered with glandular trichomes 0.1–0.3 mm long, anthers 3–3.1 mm long, ovate-oblong, the thecae slightly diverging at the base and laterally projecting into very short, broadly rounded lobes, the minute pore ca. 0.15 mm diam., slightly ventrally inclined on top of a very short beak, connective barely prolonged below the thecae, dorsally very shortly projected into a very broad, rounded or slightly emarginate appendage, lacking glands. Ovary 5-locular, inferior, apex glabrous; style ca. 7 mm long, curved, moderately covered with glandular trichomes 0.2–0.4 mm, stigma capitate. Mature fruits dark crimson at first, later maturing black, up to 7.5 mm diam, subglobose with the persistent calyx upright. Seeds not seen.

Paratypes:— PERU. Pasco: Province of Oxapampa, Dist. Oxapampa, Parque Nacional Yanachaga-Chemillén , Abra Esperanza , 2790 m, 10°32’02”S 75°20’58”W, 29 October 2010 (fl), E. Briceño & R. Rivera 341 ( HOXA!, MO!, NY!, USM) ; Sector San Alberto , camino hacia el ojo de agua, 2877 m, 10°31’45”S 75°21’08”W, 13 October 2006 (fr), L. Cárdenas & R. Francis 853 ( CUZ, HOXA!) ; aprox. 2 horas del Refugio Abra Esperanza dirección sur-este, 2972 m, 10°32’30”S 75°20’56”W, 18–19 April 2009 (fl, fr), M. Cueva & R. Rivera 555 ( HOXA, HUT, MO!, USM!) ; sector San Alberto, sendero entre Abra Esperanza y bosque esclerófilo hacia el N del refugio, 2915 m, 10°31’42.4”S 75°21’15.1”W, 21 March 2016 (fl buds), F. A. Michelangeli 2744 et al. ( HOXA!, NY!, USM!) ; sector San Alberto; sendero entre refugio Abra Esperanza y ojos de agua, 2920 m, 10.5286°S, 75.3544°W, 19 July 2017 (fl), F. A. Michelangeli et al. 2872 ( HOXA!, NY!, USM!) ; sector San Alberto, pajonal al S del Abra Esperanza , 3020 m, 10°31’42”S 75°21’15”W, 19 February 2018 (fl, fr), F. A. Michelangeli & S. Riva 2939 ( HOXA!, NY!, UFPR!; USM!) ; sector San Alberto , 2837 m, 10°31’50”S 75°21’06”W, 12 November 2010 (fl), J. Perea et al. 4709 ( HOXA!, MO!) ; Abra Yanachaga , 2900 m, 10°22’46”S 75°27’43”W, 12 June 2003, R. Vásquez et al. 28119 ( AMAZ, HOXA!, HUT!, MO!, MOL, NY!, USM) ; Abra Yanachaga , 2900 m, 10°22’46”S 75°27’43”W, 12 June 2003 (fl, fr), R. Vásquez et al. 28167 ( AMAZ, HOXA!, HUT!, MO!, MOL, NY!, USM) ; Abra Yanachaga , 10°22’ S 75°27’ W, 01 August 2003 (fl), R. Vásquez et al. 28383 ( AMAZ, HOXA!, HUT!, MO!, MOL, NY!, USM) ; Abra Yanachaga , 2870–3200 m, 10°22’46”S 75°27’43”W, 01 August 2003 (fl), R. Vásquez et al. 28425 ( AMAZ, HOXA!, HUT!, MO!, MOL, NY!, USM) ; Abra Yanachaga , 2870–3200 m, 10°22’46”S 75°27’43”W, 01 August 2003 (fl), R. Vásquez et al. 28457 ( HOXA!, MO!, NY!, USM) ; Abra Yanachaga , 2900 m, 10°22’46”S 75°27’43”W, 20 August 2004 (fl), R. Vásquez et al. 30440 ( HOXA!, MO!, NY!, USM) ; Estacion Biológica San Alberto, Abra Esperanza, 2903 m, 10°31’43”S 75°21’17”W, 4 November 2012 (fl), R. Vasquez et al., 38138 ( HOXA!, HUT, MO!, USM!). Distrito Huancabamba , Parque Nacional Yanachaga-Chemillén , Sector Abra Yanachaga , 2944 m, 10°22’49”S 75°27’42”W, 18 April 2011 (fr), E. Briceño et al. 1066 ( HOXA!, HUT, MO!, NY!, USM!) ; N of Oxapampa , on side road from Quillazú ; to summit from road head, at the Paraiso-San Francisco , cutting trail up ravine and ridge to NE, 2000–3500 m, 10°28’ S 75°22’ W, 25 June 1988 (fl), R. Foster & B. Achille 12236 ( F!, USM!) ; 2900–3000 m, 10°22’46”S 75°27’42”W, 23 November 2004 (fl buds), A. Monteagudo et al. 7800 ( HOXA!, NY!) ; 2900–3000 m, 10°22’46”S 75°27’42”W, 23 November 2004 (fr), A. Monteagudo et al. 7803 ( HOXA!, MO, NY!) ; 2900–3000 m, 10°22’46”S 75°27’42”W, 23 November 2004 (fl), A. Monteagudo et al. 7805 ( HOXA!, MO, NY!) ; parte alta de la trocha Erica, cerca a la cordillera Yanachaga , 3260 m, 10°25’46”S 75°26’07”W, 22 April 2007 (fr), A. Monteagudo et al. 13759 ( HOXA!, MO!, NY!, USM) ; 3170 m, 10°22’33”S 75°28’04”W, 24 November 2007 (fl), A. Monteagudo et al. 15962 ( HOXA!, MO!, NY!, USM!) ; parte alta del campamento Abra Yanachaga , 2940 m, 10°22’49”S 75°27’42”W, 2 December 2007 (fr), A. Monteagudo et al. 16146 ( HOXA!, HUT!, MO!, NY!, USM!) ; localidad de Lanturachi, sector Santa Barbara, camino a Milpo , 2824 m, 10°22’S 75°36’W, 10 October 2003 (fl, fr), J. Perea et al. 658 ( HOXA!, HUT, MO!, NY!, USM!) ; trail to summit of Cordillera Yanachaga, via Rio San Daniel , 2700–3000 m, 10°23’S 75°27’W, 13 July 1984 (fl), D. N. Smith 7782 ( MO, USM!) ; La Colmena-trocha Erica , 3320 m, 10°27’13”S 75°26’33”W, 19 August 2008 (fl buds), L. Valenzuela et al. 11532 ( HOXA!, HUT, MO!, NY!, USM!) ; sector Grapanazú, La Colmena , “Trocha Erica”, 3487 m, 10°25’36”S 75°26’12”W, 22 May 2012 (fr), L. Valenzuela et al. 21167 ( HOXA!, MO!, USM!) ; Sector San Daniel , en la trocha erica, 3250–3450 m, 10°25’46”S 75°26’06”W, 1 March 2008 (fr), R. Vásquez et al. 33842 ( AMAZ, HOXA!, HUT, MO!, USM!) ; Milpo , 2950–3100m, 10º23’01”S, 75º37’46”W, 31 October 2009 (fl), H. van der Werff 22901 ( HOXA!, MO!, NY!, USM!) ; Milpo , 2950–3100 m, 10º23’01”S 75º37’6”W, 31 October 2009 (fl), H. van der Werff 22972 ( HOXA!, HUT, MO!, MOL, USM!) .

Distribution, ecology, and phenology:— Miconia yanachagaensis is known from the dwarf high montane shrublands and exposed grasslands areas along the Cordillera Yanachaga and the North West portion of the Yanachaga-Chemillén National Park above 2840 m, where it seems to be a common species ( Figure 6 ). It has been found fruiting and flowering throughout the year.

Conservation Status:— Miconia yanachagaensis has an EOO of 226.86 km 2 and an AOO of 36 km 2. In spite of its reduced EEO that would place it as Endangered, given the fact that the species seems to be locally abundant, most of the populations are inside a National Park in areas not frequented by the public and under no immediate threat, we recommend that this species is temporarily considered as Least Concern ( IUCN 2001; IUCN Standards and Petitions Subcommittee 2017).

Etymology:—The specific epithet of this new species alludes to the name of the mountain range where most specimens have been collected and that also forms part of the name of the national park. Yanachaga is a Quechua word that means black bundle or black package ( INRENA 2005).

Comments:—Based on flower morphology, Miconia yanachagaensis would be placed in Miconia section Amblyharrhena Naudin (1850a: 204) Triana ex Hook. f. in Bentham & Hooker (1867: 763), particularly due to its ovate-oblong anther thecae that open by a minute terminal pore. While this section is clearly not monophyletic, most species in it are found in the Andes, concentrated in two clades (Mecranium + Anaectocalyx + Allies and Miconia III sensu Goldenberg et al. 2008 ). This new species most closely resembles a large and complicated group of species of the Miconia III clade around Miconia floribunda ( Bonpland 1816: 123) De Candolle (1828: 188) , characterized by large flowers with yellow anthers and broad, capitate or funnelform stigmas. Moreover, the majority of these species also have glandular trichomes in the filament and/or style. This species group includes several species in the Andes and it is in dire need of a careful revision. In Peru this groups also includes at least Miconia incachacana , M. glandulistyla Wurdack (1978: 287) , M. lasiostyla Gleason (1931: 243) , M. madisonii Wurdack (1972: 482) , M. modica Macbride (1929: 182) and M. terborghii Wurdack (1972: 483) . Among all these species, Miconia yanachagaensis shares with M. incachacana and M. lasiostyla the long dendritic-pedicellate trichomes on the lower leaf surface; all other species are either glabrous or have stellate or stellate-pinnoid trichomes. Miconia yanachagaensis can be distinguished from the latter two species by the flattened to terete stems (vs. quadrangular and often winged) and by the nodal line, which is annular and thick in M. yanachagaensis , and thinner and just interpetiolar in M. incachacana and M. lasiostyla . Additionally the leaves often have a revolute margin and M. yanachagaensis , while they are flat in the other two species. See diagnosis for additional differences with M. incachacana .

Previous to this work, the great majority of the specimens here cited as paratypes had been determined as Miconia griffisii Macbride (1929: 188) . While the M. griffisii also has ovate, coriaceous leaves with dendritic trichomes on the abaxial surface, and it is found in similar environments, this later species has four-merous flowers, with short and broad, white to cream-colored anthers that open by longitudinal slits, which would place it in Miconia section Chaenopleura (Richard ex de Candolle 1828: 197) Triana ex Hook.f. in Bentham & Hooker (1867: 764).

Figures

FIGURE 6. Distribution of Miconia palcazuana and Miconia yanachagaensis.

FIGURE 7. Miconia yanachagaensis. A. Fertile branch with flower buds. B. Fertile branch with flowers and young fruits. C. Flower bud. D. Flower, apical view, four stamens removed. E. Old flower, apical view, with persistent petals. F. Style and inflexed stamens in bud. G. Longitudinal section of the hypanthium plus ovary. H. Stamens, from left to right, ventral view, lateral view, ventral view of the filament and apical view of the stamen. A. Monteagudo 16057 (NY); B. Monteagudo 13759 (NY); C–H. Briceño 341 (NY).

FIGURE 8. Photos of Miconia yanachagaensis in the field. A. Fertile branch with flower buds. B. Leaf, abaxial surface. C. Young branch with annular interpetiolar ridge. D. Flower, lateral view, and buds. E. Flowers, top and lateral view. A–B. Michelangeli 2744. C. Michelangeli 2872. D–E. Michelangeli 2939.