Meriania cuzcoana Wurdack, Phytologia

Fernandez-Hilario, Robin, Goldenberg, Renato & Michelangeli, Fabián A., 2023, A synopsis of Meriania (Melastomataceae: Merianieae) in Peru, Phytotaxa 602 (1), pp. 1-101 : 26-28

6. Meriania cuzcoana Wurdack, Phytologia 13(2): 71 (1966).

Type:— PERU. Cusco: Prov. Paucartambo, laderas boscosas de Pillahuata , 2000 m, 9–10 May 1945 (fl.), C. Vargas 5107 (holotype: US! [barcode 00120364 ]; isotypes: CUZ! [2 sheets]) . ( Figures 19–20 ).

Comments:— Meriania cuzcoana can be easily recognized as the only Peruvian species of Meriania with revolute auricles at the base of the leaf blades ( Fig. 19D ). This feature is present in other Andean Meriania species (e.g., M. ardyae D.Fernández & Dellinger and M. selvaflorensis Humberto Mend. ), but none have auricles with dentate-undulate margins such as in M. cuzcoana . The presence of revolute auricles is a common feature in Axinaea species, and within that genus four species ( A. floribunda Triana, A , grandifolia Triana, A. macrophylla Triana and A. quitensis Benoist ) have auricles similar to the ones in M. cuzcoana . However, M. cuzcoana is clearly distinguished from Axinaea by the lack of inflated (bulbous) dorso-basal appendages of the stamen connectives ( Cotton et al. 2014, Dellinger et al. 2014).

The dorsal appendages of the stamen connectives in M. cuzcoana are variable in size ( Fig. 19G–H ); they can be inconspicuous as in Michelangeli et al. 1908 or evident as in Vargas 5107 (up to 0.5 mm long). Likewise, the margin of the leaf blades can be variable; it is usually entire, but it is seldom slightly denticulate. Among the Peruvian species, the most likely closest relative to M. cuzcoana is M. neillii , because both species share glabrous leaves and spreading, reddish-purple corollas. However, M. cuzcoana is distinguished by its punctiform abaxial leaf blades ( Fig. 19B ) (vs. without dots in M. neillii ), 5-merous flowers (vs. 6-merous), and stamen connectives with white descending dorso-basal appendages (vs. yellow).

The specimen Chambi & Chambi s.n. (fl. bud) has cuneate leaf bases and suprabasal venation, with the secondary veins sometimes asymmetrical, but it retains the revolute auricles with dentate-undulate margins. Although the tertiary venation pattern, inflorescence structure and flower buds are similar to those observed in M. cuzcoana , we placed this specimen with reservation here.

Distribution and phenology:— Meriania cuzcoana is endemic to southern Peru and recorded in La Convención and Paucartambo provinces (Department of Cusco), and grows in montane forests at 2000–3000 m ( Fig. 21 ). It has been collected in flower from March to August and in fruit in June.

Specimens examined:— PERU. Cusco: Prov. La Convención, Dist. Maranura, Mesapelada , 2450 m, 12°54’33”S, 72°37’06”W, 19 Apr 2004 (fl.), W. Galiano et al. 6136 ( NY!); Dist. Ocobamba, Mesa pelada, 2613 m, 12°54’13”S, 72°37’06”W, 23 Mar 2004 (fl.), L. Valenzuela et al. 3147 ( NY!); Dist. Quellouno, Lacco, 2741 m, 12°36’44”S, 72°14’37”W, 16 Jun 2006 (fl.), L. Valenzuela et al. 6904 ( NY!, USM!), same locality, 2650 m, 12°37’31”S, 72°14’03”W, 18 Jun 2006 (fr.), L. Valenzuela et al. 6939 ( CUZ!, NY!). Prov. Paucartambo, Dist. Challabamba, carretera Paucartambo-Pillcopata, Pacchayoc, 2395 m, 13°09’25.92”S, 71°35’54.24”W, 14 Jun 2012 (fl.), F. A. Michelangeli et al. 1908 ( NY!, USM!); Dist. Kosñipata, PN Manu, km 8 de la trocha unión, 2500 m, 13°05’18.60”S, 71°34’28.56”W, 29 Jul 2003 (fl.), M. Raurau et al. 71 ( ABERG!), same locality, 2500 m, 13°05’18.82”S, 71°34’28.56”W, 03 Aug 2003 (fl.), W . Farfán et al. 976 ( ABERG!, USM!), same locality, 2500 m, 13°05’38”S, 71°34’26”W, 21 Jul 2017 (fl.), F. Sinca et al. 1627 ( ABERG!), EB Wayquecha, 3000 m, 13°10’S, 71°35’W, Jul 2010 (fl. bud), P. Chambi & J. Chambi s.n. ( USM!) .

Figures

FIGURE 19. Meriania cuzcoana. A. Terminal fertile branch with inflorescence. B. Leaf blade, abaxial surface. C. Detail of abaxial leaf surface. D. Detail of the revolute leaf base, abaxial view. E. Flower bud. F. Flower at anthesis. G–H. Stamens, lateral view.A–C and E–H from W. Farfán et al. 976; D from L. Valenzuela et al. 6904.

FIGURE 20. Meriania cuzcoana. A. Leaf blade, abaxial view. B. Detail of the revolute base of the leaf blade. C. Flower at anthesis, apical view. D. Flower at anthesis, lateral view. A–D from F. A. Michelangeli et al. 1908. Photos by Fabián A. Michelangeli.

FIGURE 21. Distribution map of M. cuzcoana, M. sumatika, M. vargasii and M. vilcabambensis.