Meriania acida (Markgr.) 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 : 14-15

1. Meriania acida (Markgr.) Wurdack, Phytologia 35(1): 5 (1976).

Basionym: Graffenrieda acida Markg., Notizbl. Bot. Gart. Berlin-Dahlem 13(119): 462 (1937).

Type:— PERU. Cajamarca: Prov. Cutervo, Tambillo , 26 Aug 1878 (fl.), A. Raimondi 3341 (lectotype, designated here: USM! [accession no. 1629g ]; isolectotypes: USM! [accession nos. 1629a , 1629b , 1629c , 1629d , 1629e , 1629f , 1629h ], US!-fragment [barcode 001201396 ]). Remaining syntypes:— PERU. Cajamarca: Prov. Cutervo, Tambillo, 26 Aug 1878 (fl.), A. Raimondi 3695 (fl.) ( USM! [accession no. 1629l]), A. Raimondi 3813 ( USM! [accession nos. 1629m, 1629n, 1629ñ]), same locality and date (ster.), A. Raimondi 4844 ( USM! [accession no. 1629j ]), same locality and date (fl.), A. Raimondi 6126 ( USM! [accession no. 1629m]). COLOMBIA. Antioquia: S. Augusto , 25 Dec 1879, Kalbreyer 1293 (not located). ( Figure 8 ).

Comments:— Meriania acida is only known in Peru from the original material collected by A. Raimondi in 1878. It is characterized by its calyptrate calyces without dorsal projections ( Fig. 8E ) and campanulate, reddish-orange corollas. In Peru there are three other species with calyptrate calyces ( M. escalerensis , M. sessilifolia and M. tomentosa ). However, M. escalerensis and M. sessilifolia have spreading, deep pink to reddish-purple corollas. In addition, M. escalerensis has calyces with circumscissile dehiscence (vs. irregular in M. acida , Fig. 8E ) and stamen connectives with blunt ascending dorsal appendages (vs. absent). On the other hand, M. sessilifolia shares with M. acida the calyces with irregular dehiscence but the former is clearly distinguishable by its sessile leaves [vs. clearly petiolate, (1.5–) 2.2–3.4 cm long]. The Peruvian species most similar to M. acida is M. tomentosa , but they can be differentiated by the petal length (9–10 mm long vs. 20–24 mm long) and the shape of the descending dorso-basal appendages of the stamen connectives (acute vs. blunt).

Based on a collection made in Amazonas (Wurdack 1054), Wurdack (1964, 1976) considered M. acida to be closely related to M. denticulata (Gleason) Wurdack , from Ecuador, because both share subcalyptrate calyces and small dorsal projections on the calyx. However, after a detailed analysis we recognized Wurdack 1054 to be an undescribed species, and proposed M. juanjil ( Fernandez-Hilario et al. 2022) . Meriania acida is easily distinguishable from M. juanjil by its calyptrate calyx without dorsal projections (vs. subcalyptrate with acute dorsal projections), leaf blades 5–8 cm wide (vs. 2.7–3 cm wide) and petals 9–10 mm long (vs. 11–13.5 mm long).

Nomenclatural notes:— Markgraf (1937) cited in the protologue five Peruvian specimens (Raimondi 3341, 3695, 3813, 4844 and 6126) and one Colombian specimen (Kalbreyer 1293), so these specimens must be considered as syntypes conforming with Art. 9.6 of the ICN ( Turland et al. 2018). 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. According to Art. 9.3 and 9.12 of the ICN ( Turland et al. 2018), we chose Raimondi 3341 for lectotypification, because this specimen has the highest number of fertile sheets (duplicates).

Distribution and phenology:— Meriania acida is apparently restricted to northern Peru and only present in the department of Cajamarca ( Fig. 9 ). Markgraf (1937) cited one Colombian specimen in the protologue of M. acida . However, none of the species currently recognized for Colombia (see Mendoza-Cifuentes 2021) matches the concept we used here for M. acida . Although the original material collected by A. Raimondi does not give details of its habitat, Meriania acida probably grows in montane forest relicts. It has been collected in flower in August.

Specimens examined:— PERU. Cajamarca: Prov. Cutervo, Tambillo , 26 Aug 1878 (ster.), A. Raimondi 3536 ( USM!), same localty and date (ster.), A. Raimondi 6240 ( USM!), same localty and date (ster.), A. Raimondi 6319 ( USM!) .

Figures

FIGURE 8. Meriania acida. A. Terminal fertile branch with inflorescence. B. Leaf blade, abaxial view. C. Detail of abaxial leaf surface. D. Inflorescence with flower buds. E. Flower bud (left) and calyx with irregular dehiscence (right). F. Petal. G. Stamen, lateral view.A–G from A. Raimondi 3695.

FIGURE 9. Distribution map of M. acida, M. callosa, M. dazae, M. drakei, M. franciscana, M. juanjil and M. peltata.