Meriania tetraquetra Triana, Trans. Linn. Soc. London

Fernandez-Hilario, Robin, Goldenberg, Renato & Michelangeli, Fabián A., 2023, A synopsis of Meriania (Melastomataceae: Merianieae) in Peru, Phytotaxa 602 (1), pp. 1-101 : 76

29. Meriania tetraquetra Triana, Trans. Linn. Soc. London 28(1): 66 (1871) [1872]. Type :— PERU. Amazonas: Prov. Chachapoyas, without locality, no date (fl.), M. Mathews s.n. (holotype: K! [barcode K000329445 ]; isotypes: BR! [barcode 000005201983], F!-fragment [accession no. 1026686], G-probably destroyed [negative at F]). ( Figures 61–62).

Comments:— In the protologue of this species, J. J. Triana described it as glabrous (“ glaberrimus ”) but it is sparsely to densely puberulent ( Fig. 61C). Meriania tetraquetra is characterized by its quadrangular internodes, nodes without interpetiolar flaps, ovate to oblong and slightly bullate leaf blades (9.3–)13–35 × (4.7–) 9.1–19.7 cm, venation with two pairs of secondary veins and an additional pair of faint submarginal veins ( Fig. 61D), calyces with small conic dorsal projections ( Fig. 61E–F), spreading, reddish-purple corollas, isomorphic stamens, and stamen connectives with one triangular descending dorso-basal appendages ( Fig. 61H). The most closely related Peruvian species is M. rugosa , but it is distinguished by its elliptic leaf blades 10.3–25.4 × 4.2–10.6 cm and venation with one pair of secondary veins.

Macbride (1941), in his treatment of Meriania for Peru, placed Weberbauer 7048 (which we have published as M. megaphylla ) under M. tetraquetra . However, this specimen has quadrangular and winged internodes, and nodes with interpetiolar flaps. Probably because of this misidentification he considered M. tetraquetra related to M. radula (“ nearly the same as M. radula and perhaps not specifically separable ”). Nevertheless, M. tetraquetra and M. megaphylla are not related to the M. radula complex, because of their flowers with spreading, reddish-purple corollas (vs. campanulate, deep red) and stamen connectives with descending dorso-basal appendages (vs. perpendicular to the thecae).

Distribution and phenology:— Meriania tetraquetra is endemic to northern Peru (Departments of Amazonas and San Martín) and grows in montane forests at 2240–3000 m ( Fig. 44). It has been collected in flower in May, August and September, and in fruit in September.

Specimens examined:— PERU. Amazonas: Prov. Chachapoyas, Dist. Leymebamba, alrededores de la Fila de la Culebra, 2246 m, 06°43’03.18”S, 77°37’26.76”W, 05 Sep 2004 (fl.), V . Quipuscoa et al. 3268 ( HUT!). Prov. Rodríguez de Mendoza, Dist. Vista Alegre, Área de Conservación Regional Vista Alegre , camino hacia Cedrushco , a una hora del campamento Quebrada Salas , 2403 m, 06°06’24.01”S, 77°25’04.36”W, 17 Aug 2012 (fl.), R . Fernandez-Hilario et al. 251 ( MOLF!, NY!, UPCB!), a media hora del campamento Cedrushco, quebrada Salas , 2361 m, 06°06’23.66”S, 77°24’41.22”W, 21 Aug 2012 (fl.), J. L . Marcelo-Peña et al. 7103 ( MOLF!) . Cajamarca: Prov. Celendín, Dist. Pallán, La Succha, 2878 m, 06°37’58.23”S, 78°22’02.90”W, 02 Jun 2017 (ster.), L . Dávila 3309 ( UNC!). Prov. Chota, Dist. Chadín, La Unión – Bosque la Playa y alrededores, 2688–2720 m, 06°26’07.11”S, 78°23’38.79”W, 22 Jul 2010 (ster.), L . Dávila et al. 1309 ( UNC!); Dist. Paccha, CP Quidén y Rejopampa, 2500 m, 06°30’20.28”S, 78°24’09.31”W, 19 May 2012 (fl.), L . Dávila 2368 ( UNC!). Prov. Cutervo , Dist. Cutervo, CP San Cristóbal del Nudillo , sector el Mirador y propiedad de Darwin Horna, 2690 m, 06°18’33.68”S, 78°51’40.71”W, 01–03 Nov 2012 (ster.), L . Dávila 2502 ( UNC!) . San Martín: Prov. Mariscal Cáceres, PN Río Abiseo , across river from La Playa camp, 2600 m, 01 Sep 1985 (fr.), K . Young 1531 ( MOLF!). Prov. Huallaga, Dist. Bolivar, Surrounding “Pampa Hermosa” around old Chacha and Inca settlement, 3000 m, 07°02’07”S, 77°40’29”W, 24 May 2011 (fl.), R . Bussmann et al. 17071 ( F!, HAO!, MO!, NY!, US!).