Peperomia chazaroi G.Mathieu & T.Krömer, 2015

Mathieu, Guido, Vergara-Rodríguez, Daniela, Krömer, Thorsten & Karger, Dirk Nicolaus, 2015, Peperomia (Piperaceae) novelties from Veracruz State, Mexico, Phytotaxa 205 (4), pp. 268-276 : 269-272

Peperomia chazaroi G.Mathieu & T.Krömer , spec. nov. ( Fig. 1 (A, B, C), 2).

Peperomia hispidula (Sw.) A.Dietr et Peperomia hispiduliformis Trel. simile, ab eis differt habitu repente et foliis glabris vix villosisve, plerumque peltatis, 7-nerviis margine paralelle anastomosantibus. Type:— MEXICO. Veracruz State, mun. Acajete, Sierra Chiconquiaco, Loma del Muerto, Cascada del Alto Pixquiac [Rancho Las Piedras], 19°32’09”N, 97°04’34.2”W, 2,830 m, 15 Sep. 2010, M. Cházaro et al. 9868 (holotype BR!, isotypes GENT!, MEXU!, MO!).

Delicate, creeping, lithophytic herb, 3–5 cm tall. Stem filiform, terete, rooting from the nodes except from the most apical ones, watery green or sometimes slightly pinkish red striped, internodes 1.5–3 cm long, glabrous except for the villous multicellular trichomes at the nodes. Leaves alternate, petioles (0.5–) 1–2 cm long, scarcely villous or glabrous (except for some villous trichomes near the base and at the lamina insertion), lamina membranous, orbicular to slightly ovate or often reniform, quite uniform in size, diam. ca. 1 cm, apex rounded or slightly obtuse, base cordate, usually peltate 1–1.5 mm from the basal margin, sometimes subpeltate, both sides glabrous or scarcely villous, margin eciliate, in young leaves some solitary trichomes adaxially, main nerves 7, the most basal ones weaker, running into the lobes and continuing in a tiny anastomosing nerve parallel to the entire margin, villous trichomes at the main nerves abaxially, most dense near the leaf base and continuous with the trichomes of the apical petiole, light green adaxially, whitish green abaxially. Inflorescences solitary, terminal and leaf opposed, peduncle filiform, 1–2 cm long, glabrous or scarcely villous, rachis filiform, 1–2 cm long, glabrous, loosely flowered. Floral bract orbicular, centrally peltate, rather small, ca. 0.25 mm diam. Ovary long ellipsoid, style conical, stigma apical. Stamens with long filaments in anthesis. Fruit ellipsoid, pericarp initially glabrous, hispid when maturing.

Etymology— The specific epithet is chosen in honor of Miguel de Jesús Cházaro-Bazañez, Mexican botanist and Agavaceae specialist from the Universidad Veracruzana and the Universidad de Guadalajara, who collaborated in all known collections of this species.

Distribution, habitat and IUCN Red List category— The new species is considered as endemic to the central montane region of Veracruz located around the capital city of Xalapa, as it is known only from four collections (AOO: 57.11 km 2) made at the same locality at an elevation of 2,700 –2,830 m. It seems to prefer a moist, shady habitat (narrow canyons, cave entrances) where it grows on rock walls together with ferns and mosses ( Fig. 1 B ). Because of the ongoing changes in land use of its pine-oak forest habitat and its very small distribution area, which is not included inside the Veracruz protected areas network, it is considered as Endangered (EN) B2ab(ii,iii).

Relationships— Peperomia chazaroi is morphologically close to P. hispidula ( Swartz 1788: 15) Dietrich (1831: 165) and P. hispiduliformis Trelease (1941: 295) ( Tab. 1).

Both the latter are widespread species reported from Mexico to Argentina and Brazil. P. hispidula is reported additionally from the Caribbean Islands.

P. chazaroi is distinct in the creeping habit, the usually peltate leaves, the scarce villous trichomes and the nervation pattern.

Additional specimens studied— MEXICO. Veracruz State, mun. Acajete, Cofre de Perote, Alto Pixquiac , en una cueva en la barranca Cuesta del Vaquero , 2,700 m, 30 Dec. 1990, M. Cházaro & R. Cházaro 6519 ( MICH!, XAL!) ; barranca Cuesta del Vaquero , 2700 m, 14 Jun. 1986, M. Cházaro 3712 ( XAL!) ; mun. Acajete, Sierra Chiconquiaco, Rancho Las Piedras , Loma del Muerto , Cascada del Alto Pixquiac , 19°32’09”N, 97°04’34.2”W, 2700 m, 15 Sep. 2010, T. Krömer et al. 3994 ( BR!, GENT!, MEXU!) .

Figures

FIGURE 1. Peperomia chazaroi (A, B, C). A) Miguel de Jesús Cházaro-Bazañez at type locality. B) Plants in habitat. C) Detail of the inflorescence. Peperomia parastriata (D, E, F). D) Plant in habitat. E) Inflorescences. F) Detail of the infrutescence. Peperomia vazquezii (G, H, I). G) Plants in limestone wall habitat. H) Inflorescences. I) Detail of the inflorescence. (Photographs A–H by T. Krömer; I by D.H. Jimeno-Sevilla).