Meriania rubriflora Michelang. & R.Goldenb., Phytotaxa

Fernandez-Hilario, Robin, Goldenberg, Renato & Michelangeli, Fabián A., 2023, A synopsis of Meriania (Melastomataceae: Merianieae) in Peru, Phytotaxa 602 (1), pp. 1-101 : 60-61

22. Meriania rubriflora Michelang. & R.Goldenb., Phytotaxa 374(3): 190 (2018).

Type:— PERU. Pasco: Prov. Oxapampa, Dist. Huancabamba, Sector Oso Playa, caminho a la parcela Oso Playa , 2565 m, 10°19’05”S, 75°36’28”W, 25 Jun 2006 (fl.), L. Cárdenas, A. Monteagudo, A. Peña, J. Mateo & R. Francis 458 (holotype: USM!; isotypes: CUZ!, HOXA! [accession no. 26984 ], MO!, MOLF! [barcode 000023 ], P! [barcode P04801621 ], USM!) . ( Figure 50 ).

Comments:— Among Peruvian species of Meriania , this species is unusual by the combination of developed interpetiolar flaps ( Fig. 50D ), large pendulous inflorescences (27–34 cm long) ( Fig. 50A ), 4-merous flowers with red corollas. Although some Andean ( M. arizae , M. mexiae , M. sararensis Humberto Mend. & Fern.Alonso and M. selvaflorensis ) and Brazilian ( M. baumgratziana R.Goldenb. & Michelang. , M. glazioviana Cong. , M. longipes Triana and M. tetramera Wurdack ) species of Meriania exhibit pendulous inflorescences, this characteristic is more common in Axinaea . Many species of Axinaea have pseudo-lateral inflorescences, which can be interpreted as somewhat pendulous (see Cotton et al. 2014), but there are species that have evident and large pendulous inflorescences. Peruvian species with this characteristic are A. crassinoda Triana , A. dependens Ruiz & Pav. Ex D.Don , A. fernando-cabiesii Bussmann, J.A.Gruhn & A.Glenn , A. mertensioides Wurdack , A. oblongifolia (Cogn.) Wurdack , A. pendula E.Cotton , A. reginae Bussmann, J.A.Gruhn & A.Glenn and A. sessilifolia Triana. Within this group only A. crassinoda , A. dependens and A. pendula have developed interpetiolar flaps, 4-merous flowers and red corollas. Meriania rubriflora (Department of Pasco) is morphologically close to A. dependens (Departments of Huánuco and Pasco) by sharing leaf blades and inflorescences similar in size and shape. However, the former can be differentiated by its branches sparsely to moderately covered with glandular projections (vs. moderately to densely furfuraceous in A. dependes ) and petals 11.7–12.3 mm long (vs 8–10 mm long).

Although Michelangeli & Goldenberg (2018) considered M. rubriflora as a species of Meriania based on its stamens without evident inflated (bulbous) connectives ( Fig. 50E ), Cotton et al. (2014) in their revision of Axinaea indicated that species with 4-merous flowers have stamen connectives with elliptical appendages instead of the inflated (bulbous) dorso-basal appendages characteristic of Axinaea . Even the illustrations of A. crassinoda (see drawing on Mathews 3212 in K) or A. pendula (see Fig. 58 in Cotton et al. 2014) show stamen connectives like those of M. rubriflora . The species of Axinaea with 4-merous flowers can be considered intermediate forms between Axinaea and Meriania , which would also be the case of the Meriania macrophylla complex by their antepetalous stamens with inflated (bulbous) connectives. Recent phylogenetic studies have placed Axinaea species within Meriania ( Dellinger et al. 2018, 2019; Michelangeli et al. 2022), and further studies are needed to resolve whether Meriania and Axinaea should be considered separate genera.

Distribution and habitat:— Meriania rubriflora is endemic to central Peru (Department of Pasco) and occurs in montane forests at 2480–2560 m ( Fig. 11 ). It has been collected in flower in June.

Specimens examined:— PERU. Pasco: Prov. Oxapampa, Dist. Huancabamba, Sector Oso Playa , margen izquierda del rio, 2497 m, 10°19’28”S, 75°36’07”W, 20 Jun 2006 (fl.), L . Cárdenas 407 ( CUZ!, HOXA!, MOLF!), remanente de bosque, 2480 m, 10°19’21”S, 75°34’11”W, 26 Jun 2004 (fl.), R . Rojas & J . Perea 3073 ( HOXA!, NY!), de amortiguamiento del PN Yanachaga Chemillén, 2567 m, 10°19’05”S, 75°36’28”W, 25 Jun 2008 (fl. bud), A . Monteagudo et al. 16516 ( HOXA!) .

Figures

FIGURE 11. Distribution map of M. amischophylla, M. bicentenaria, M. rubriflora, M. vasquezii and M. weberbaueri.

FIGURE 50. Meriania rubriflora. A. Terminal fertile branch with inflorescence. B. Leaf blade, abaxial view. C. Detail of the abaxial leaf surface. D. Detail of the interpetiolar flap. E. Stamen in lateral view. F. Inflorescence branch. G. Flower with petals and stamens removed. B from J.L. Marcelo et al. 6528; A, C–G from L. Cárdenas et al. 458; B from R. Rojas & J. Perea 3073.

FIGURE 58. Meriania sumatika. A. Terminal fertile branch with inflorescence. B. Flower at anthesis, apical view. C. Leaf blade, abaxial view. D. Infructescence branch. E. Antepetalous stamen, lateral view, with detail of the dorso-basal appendage, frontal view (above). F. Antesepalous stamen, lateral view, with detail of the dorso-basal appendage, frontal view (above). G. Hypanthium and calyx in lateral view. A–C from W. Galiano et al. 6410; D–G from P. Núñez & J. Arque 8369. Drawing by Leticia Lajo (B).