Meriania rugosa Markgr.

Fernandez-Hilario, Robin, Goldenberg, Renato & Michelangeli, Fabián A., 2023, A synopsis of Meriania (Melastomataceae: Merianieae) in Peru, Phytotaxa 602 (1), pp. 1-101 : 62-64

23. Meriania rugosa Markgr. , Notizbl. Bot. Gart. Berlin-Dahlem 13(119): 460 (1937).

Type:— PERU. Amazonas: Prov. Rodríguez de Mendoza, valle de Huayabamba , Mar 1869 (fl.), A. Raimondi 1866 (lectoype, designated here: USM! [accession no. 1670a ]. Remaining syntype:— PERU. Amazonas: Prov. Rodríguez de Mendoza, entre Cochamal y Sta. Rosa, valle de Huayabamba , Apr 1869 (ster.), A. Raimondi 1796 ( USM! [accession no. 1670b ]) . ( Figures 51– 52 ).

Comments:— We have placed a group of specimens collected in the south of the department of Amazonas under M. rugosa s.l. All specimens of M. rugosa share elliptic leaf blades, suprabasal venation, one pair of secondary nerves ( Fig. 51B ), 5-merous flowers with spreading, reddish purple corollas, and isomorphic stamens. However, there is a high amount of variability across localities, sometimes in very close populations; Boeke 2052 and Bussmann et al 16614 are located across the Lajasbamba mountain range (Chachapoyas province), and have densely puberulent stems, bullate leaf blades and stamen connectives with dentiform dorsal appendages. The type of M. rugosa (Rodríguez de Mendoza province) and van der Werff et al. 17006 (Chachapoyas province) show slightly bullate leaf blades, calyces with blunt dorsal projections 2–3 mm long ( Fig. 51F and H ), anthers 9–9.5 mm long, and stamen connectives without dorsal appendages ( Fig. 51G ). The northern specimens Michelangeli et al. 1704 and van der Werff et al. 24958 (Bongará province) have flat leaf blades, calyces with obsolete dorsal projections ( Fig. 51E ), anthers 9.5–10 mm long, and stamen connectives with dentiform dorsal appendages ( Fig. 51D ).

Although there are clearly distinguishable forms that could be recognized as distinct entities (species or subspecies), in the central distribution of M. rugosa s.l. there are specimens that could be considered intermediate forms. For example, Michelangeli et al. 1725 (Chachapoyas Province) has flat leaf blades, calyces with small conic dorsal projections ca. 0.5 mm ( Fig. 51J ), stamen connectives with dorsal appendages as a mere hump to dentiform ( Fig. 51I ), and connectives prolonged below the thecae ca. 0.5 mm. Also, Pennington et al. 17862 (Rodríguez de Mendoza Province) has puberulent stems and abaxial leaf blades, calyces with blunt dorsal projections ca. 2 mm long, anthers 5–6 mm, and stamen connectives without dorsal projections. For this reason, we place all forms mentioned here under our concept of M. rugosa s.l.

Based on all of this, perhaps the best option is to consider M. rugosa as a highly variable species, but united by elliptic leaf blades, suprabasal venation, one pair of secondary nerves, 5-merous flowers with spreading, reddish purple corollas, and isomorphic stamens. The Peruvian species likely closely related to M. rugosa s.l. are M. penningtonii and M. tetraquetra (see comments under this species for difference). Meriania penningtonii is clearly differentiated by its ovate leaf blades (vs. elliptic in M. rugosa ), basal venation (vs. suprabasal), quadrangular and 4-winged internodes (vs. quadrangular) and callose dorsal projections on the calyx (vs. absent, small conic or blunt).

Nomenclatural notes:— Markgraf (1937) cited in the protologue of M. rugosa , two specimens, Raimondi 1796 and 1866 as types, both of which we have located in the A. Raimondi collection housed at USM. The A. Raimondi collection housed in USM corresponds to the specimens that were sent on loan to Berlin in 1926 ( Anonymous 1939, 1942), so they may have been seen by F. Markgraf. These specimens must be considered as syntypes conforming with Art. 9.6 of the ICN ( Turland et al. 2018). According to Art. 9.3 and 9.12 of the ICN ( Turland et al. 2018), we chose as lectotype the only sheet with flowers (Raimondi 1866).

Distribution and phenology:— Meriania rugosa is endemic to northern Peru (Department of Amazonas) and occurs in montane forests at 1880–3300 m ( Fig. 44 ). It has been collected in flower in February, March, April, May, July, August, and November, and in fruit in June and July.

Specimens examined:— PERU. Amazonas: Partly along main road Jumbilla-Pedro Ruiz, partly along road to Tialango, 2080 m, 05°52’31”S, 76°46’36”W, 03 Nov 2012 (fl.), H. van der Werff et al. 24958 ( HOXA!, NY!); Road E of Chachapoyas between Pipos and Molinopampa , 1980–2340 m, 06°15’S, 77°40’W, 14 Feb 1985 (fl.), J. Luteyn & E. Cotton 11402 ( NY!, USM!); Izuchaca , 1880 m, 06°19’40”S, 77°31’05”W, 11 Apr 2001 (fl. bud), H. van der Werff et al. 16943 ( NY!). Prov. Bongará , 0.5–2 km al sur de Nuevo Gualulo, 2400– 2108 m, 05°51’11.6”S, 77°54’19.5”W, 11 Mar 2012 (fl.), F. A. Michelangeli et al. 1704 ( NY!, USM!); Dist. Florida , trocha rumbo a CP Perlamayo, 05°47’10”S, 77°54’49”W, 30 Aug 2022 (fl.), R. Fernandez-Hilario et al. 2275 ( MOLF!). Prov. Chachapoyas, moist scrub forest on south side of Molinopampa-Diosan pass, 2700–3100 m, 08 Aug 1962 (fl.), J. Wurdack 1617 ( F!, NY!, US!, USM!); remnants of forest a few km past Molinopampa , 2450 m, 06°12’S, 77°40’W, 13 Apr 2001 (fl.), H. van der Werff et al. 17006 ( MOLF!, NY!, USM!); scrub forest along Río Ventilla 1–2 km, west of Molinopampa , 2350–2400 m, 23–25 Jul 1962 (fr.), J. Wurdack 1483 ( F!, NY!, US!, USM!); Dist. Leymebamba, camino rumbo hacia la ACP Los Chilchos , 3300 m, 06°47’25”S, 77°45’40”W, 26–29 Jun 2022 (fl. bud), R. Fernandez-Hilario et al. 2350 ( MOLF!), Leimebamba-Lajasbamba trail, 28 Jun 1977 (fr), J. Boeke 2052 ( NY!, US!, USM!), trail from Atalaya to Leymebambaa , 2800 m, 06°44’39”S, 77°47’18”W, 04 Jul 2010 (fl.), R. Bussmann et al. 16614 ( NY!); Dist. Molinopampa, 2–3 km al oeste del pueblo, 38 km de Chachapoyas, a lo largo del Río Ventilla , 2400 m, 06°12’36.8”S, 77°40’49”W, 12 Mar 2012 (fl.), F. A. Michelangeli et al. 1725 ( NY!, USM!). Prov. Rodríguez de Mendoza , Dist. San Nicolás, carretera R. de Mendoza Rioja, Laguna Huamanpata, 2000 m, 06–09 May 2005 (fl.), T. Pennington et al. 17862 ( MOLF!) .

Figures

FIGURE 44. Distribution map of M. penningtonii, M. rugosa and M. tetraquetra.

FIGURE 51. Meriania rugosa. A. Terminal fertile branch with inflorescence. B. Leaf blade, abaxial view. C. Detail of the abaxial leaf surface. D. Stamen, lateral view, with detail of the dorsal appendage (above). E. Flower with petals and stamens removed. F. Flower bud. G. Stamen, lateral view. H. Flower with petals and stamens removed. I. Stamen, lateral view, with detail of the dorsal appendage (above). H. Flower with petals and stamens removed. A–C and I–J from F. A. Michelangeli et al. 1725; D–E from F. A. Michelangeli et al. 1704; F–H from H. van der Werff 17006.

FIGURE 52. Meriania rugosa. A. Leaf blade, adaxial view. B. Detail of the base of the leaf blade. C. Detail of the inflorescence. D. Inflorescence with flowers at anthesis. A from R.W. Bussmann et al. 16614, B and D from F.A. Michelangeli et al. 1725, C from F.A. Michelangeli et al. 1704. Photos by Rainer W. Bussmann (A) and Fabián A. Michelangeli (B–D).