Peperomia pilocarpa Pino, Samain & L.E. Alomia, 2023

Pino Infante, Guillermo Eloy, Samain, Marie-Stephanie, Alban Castillo, Joaquina Adelaida & Alomia Collazos, Luis Enrique Aaron, 2023, Species of Peperomia (Piperaceae) from the Sana River Valley, Peru, PhytoKeys 225, pp. 1-40 : 1

11. Peperomia pilocarpa Pino, Samain & L.E. Alomia sp. nov.

Fig. 7A-G

Type.

Peru, Dept. Cajamarca, prov. San Miguel, dist. Niepos: road from La Florida to Niepos , 1613 m, 06°54'03.3"S, 79°07'33.5"W, 26 Jul 2020, G. Pino & L.E. Alomía 3217 (USM 333265!); Same collection, 28 Aug 2022, G. Pino et al. 3646 (USM 333266!) .

Diagnosis.

Perennial, semi-succulent, prostate caespitose herb similar in habit to P. cacaophila , but differs mainly in leaf shape, which is widely obovate to elliptic or rotundate and sometimes slightly acuminate, compared to the ovate lamina and constantly acuminate apex of this species, leaves are flatter and less succulent, slightly puberulous compared to the canaliculate, glossy leaves of P. cacaophila . Stems are not terete as in this species but with two low prominent wings. Seeds are dimorphic, normal seeds are very similar in shape to the seeds of P. sagasteguii , modified seeds (probably galls) are conspicuous, large up to 2.5 mm long, bright green to brownish, densely covered with white trichomes.

Description.

Perennial semi succulent terrestrial or semiepiphytic herb, living in the shade and on abundant decayed vegetal matter, 10-15 cm tall, up to 25 cm when flowering. Roots basal and from basal nodes, very fibrous, light gray, 0.2-0.3 mm diam., 1-3 cm long. Stem mainly prostate, straight, procumbent when vegetative and decumbent sometimes at tips, up to 45 cm long or more, subterete, 2.5-3.5 mm diam. at the base, gradually tapering to 1.5-2 mm at the apex, dull olive green, reddish where exposed, with two not very prominent longitudinal wings decurrent with leaf petioles, internodes 1-5 cm, rarely with alternate branches from the base or every 10-15 cm. Leaves alternate, spirally attached one per internode, glabrous to slightly puberulous, present all along the stem; petiole circular in section, 0.8-1.5 cm long, 1-1.5 mm diam., with two lateral not prominent wings decurrent with stem, straight or slightly recurvate, lamina flat, widely obovate to oblong, (2-) 3-6 cm long, 1-3.5 mm thick, (1-)1.5-2.5 cm wide at distal third, (1.5-)2.8-3.8 cm wide at the middle, (1-)2-3 cm wide at proximal third, apex acute, obtuse in some leaves and slightly acuminate in larger leaves, subemarginate at tip, base rounded; adaxially dull green, 3-palmatinerved, nerves slightly depressed; margin completely entire; abaxially light green, obscurely 3-palmatinerved, central nerve and proximal thirds of lateral nerves somewhat darker in color. Inflorescence a single terminal spadix appearing from November to December; peduncle terete or slightly funnel-shaped distally, sometimes reddish and obscurely furrowed, 7-12 mm long, 2-2.5 mm diam., with a small oval bract at the base, similar to leaves, rachis 6-10 cm long, 1.5-2.5 mm diam., light green. Floral bracts narrowly oval to subpentagonal, subacute, light green, 0.6-0.7 mm long, 0.5-0.6 mm wide. Stamens: filaments transparent, 0.2 mm diam., 0.4-0.5 mm long, anthers ovoid, 0.4-0.45 mm long, 0.25-0.3 mm wide, bright red at first, then white. Normal fruit globose, 0.7-0.8 mm long, 0.6-0.7 mm diam., brown, covered of white 0.05 mm long whitish papillae up to distal third of fruit, style conical, light brown. Modified fruit, 2-2.5 mm long, 1.2-1.5 mm diam., bright green to brownish, minutely and densely covered with white 0.1-0.2 long trichomes, style prominent, bright green, 0.2-0.25 mm long, 0.3-0.4 mm diam., stigma dark, ripening from February to July.

Distribution and habitat.

Plants grow from 1500 to 1600 m of the middle course of the Saña River valley, in the remnants of montane forest, mostly epiphytic.

Phenology.

Inflorescences appear from October to March; fruits ripen from November to April.

Etymology.

The epithet recalls the hairy surface of the modified fruits of this species, from the Latin pilus (hair) and Greek καρπός (fruit).

Notes.

This specimen at first was considered a probable hybrid because it shows intermediate features between P. emarginulata and P. cacaophila . However, although those two species share their habitat to some extent they are found at lower altitudes and never close to P. pilocarpa . Instead, this species appears within the range of P. vivipara , but it seems not to be related to it. Another interesting fact is that most fruits are modified to form hairy galls. The etiology of these galls remains unknown.

This species belongs to Peperomia subg. Micropiper (Miq.) Miq. ( Frenzke et al. 2015).

Additional specimen examined.

Peru, dept. Cajamarca, Prov. San Miguel, dist. La Florida: Road from Monteseco to Chorro Blanco, 1545 m, 6°50'51.3"S, 79°06'23.5"W, 10 Feb 2023, G. Pino & L.E. Alomía 3830, (USM 333267).

Figures

Figure 7. Peperomia pilocarpa A plant in habitat with assurgent stems B decumbent plant C young plants showing terminal inflorescence D plant ex-situ in anthesis showing normal inflorescence and inflorescence with galls E detail of leaves F spadix at the beginning of anthesis G mature spadix with galls and seeds. Details: (above, normal seed; below, gall with trichomes).