Peperomia pseudoasarifolia Callejas & G. Mathieu, 2018

García-Martínez, Roberto, Beutelspacher-Baigts, Carlos R., Posada, Ricardo Callejas- & Mathieu, Guido, 2018, Two new lithophytic species of the genus Peperomia (Piperaceae) from the state of Chiapas, Mexico, Phytotaxa 338 (1), pp. 109-116 : 112-114

Peperomia pseudoasarifolia Callejas & G. Mathieu sp. nov. ( Fig. 3 & 5 ).

Peperomia pseudoasarifolia is morphologically close to P. asarifolia Schlechtendahl & Chamisso. It differs by floral bracts and fruits lacking hyaline dots in contrast to orange hyaline dotted leaves, floral bracts and fruits in P. asarifolia . It also differs by leaf-opposed spadices, not seen in P. asarifolia and by (immature) fruits, on small mounds of the rachis, not sessile as in P. asarifolia .

Type:— MEXICO. Chiapas, Municipality Motozintla, 11 km along the road from Motozintla to El Porvenir and Siltepec, [est. 15°24’N 92°18” W], 2100 m, 27 Jun 1972, D. E. Breedlove 25752. (Holotype: MO!; isotypes: F!, MICH!, TEX!) .

Terrestrial lithophytic herb, up to 30 cm tall ( Fig. 3 & 5 ). Tuber buried, with fibrous roots all over its surface. Stem erect, 1–2 cm long, 6–8 mm diam., branching near the base; main branches 2–3, 15–20 (–30) cm long, simple or with secondary branches, 3–5 cm long; basal internodes ≤ 20 cm, apical internodes 4–6 cm, glabrous, lacking hyaline dots, pale green when dry, leaf scars discrete. Leaves alternate, uniform in shape; lamina membranous, wide ovate to almost orbicular, (4–) 7–14 × (3–) 5–12 cm, terminal leaves smallest, apex usually short acuminate or rarely acute, base deeply cordate and lobed ( Fig. 3b ), shortly puberulent near the margin ( Fig. 3c ), lacking hyaline dots, brownish-green adaxially and pale green, almost white abaxially when dry; lobes not overlapping, forming a 6–10 mm deep sinus; margin ciliate with short erect trichomes 0.2 mm long (3–5 cells); 11-palmatinerved, the most lateral ones diverting at an angle of 70°, the ones closest to the central nerve diverting at an angle of 35°–45°, main nerves branching 1–3 times, secondary and tertiary ones forming areoles of 1–2 cm length, anastomosing close to margin, central nerve with 2–3 pairs of nerves between middle and distal third, nerves sunken on adaxial and abaxial leaf surface; petioles 6–11 cm long on the main branches, 3–4 cm long on the secondary branches, not decurrent at the stem, glabrous, lacking hyaline dots, pale green when dry. Inflorescences simple, leaf-opposed or axillary, spadices 3–6 per node, one spadix leaf-opposed and the other ones emerging together from the leaf axil, erect, more or less rigid, white, sessile or with a short peduncle 2–8 mm long, green, glabrous, subtended by persistent bracteole, ovate, 3–4 mm long, glabrous; rachis 1.8–2.5 cm long in anthesis, 3.5–6.5 cm long when fruiting, 1 mm diam., glabrous, lacking hyaline dots, dull green and profoundly grooved when dry. Flowers arranged in whorls, densely disposed in anthesis, loosely arranged when fruiting, on small mounds of the rachis; floral bracts orbicular, 0.3–0.4 mm diam., partly covering the pistil, ovary ovoid, 0.2 mm diam., style conical, stigma terminal, central, sessile, fimbriate; anthers 0.2 mm long, filaments 0.3 mm long. Fruit (immature) on small mounds of the rachis, pseudopedicel absent ( Fig. 3d ).

Etymology— The Greek prefix ‘Pseudo-’ [= referring, but not equaling] in the specific epithet alludes to a close resemblance, in this case with P. asarifolia Schlechtendahl & Chamisso.

Distribution and ecology— So far, P. pseudoasarifolia is only reported from the most southeastern part of Chiapas. According to this distribution it is not unlikely that the species can also be found in Guatemala. The species occurs in montane cloud forests where it prefers a rocky substrate in shady canyons. Elevation 1500-2100 m.

Paratypes — MEXICO. Chiapas, Municipality Escuintla, Mount Ovando [est. 15°24’45”N 92°36’50”W], 2000 m, 01-16 Jul 1940, E. Matuda 4211 ( CHIP!, F!, MEXU!, MICH!, MO!, NY!) ; Municipality La Concordia, El Triunfo reserve , trail campamento El Triunfo-Finca Prusia, 15°37’N 92°48’W, 1900 m, 12 Nov 2004, N. Martínez Meléndez 581 ( HEM!, MO!) ; Municipality Mapastepec, Rio Sisilar , SE of El Triunfo Reserve [est. 15°39’13”N 92°51’50”W], 1550 m, 13 May 1982, J. I. Calzada et al. 8900 ( XAL!) ; Municipality Motozintla, Cerro Boquerón [est. 15°11” N 92 °17” W], C. A. Purpus 6953 ( BM!, US!).

Note— Already around 1937, William Trelease recognized this to be a distinct species for which he suggested the name Peperomia purpusii (ined.) ( Mathieu, 2007: 407).

Figures

FIGURE 3. Peperomia pseudoasarifolia: a) habit of the plant, b) detail of the leaf base, c) detail of the leaf margin, d) detail of the rachis with fruits (Based on D.E. Breedlove 25752 [MO]).

FIGURE 5. Herbarium collection of Peperomia pseudoasarifolia sp. nov. from Escuintla, Chiapas (E. Matuda 4211, MICH).