Peperomia calcicola Marcusso, 2020

Marcusso, Gabriel Mendes, Melo, Pablo Hendrigo Alves De & Lombardi, Julio Antonio, 2020, Peperomia calcicola (Piperaceae), a new species from limestone outcrops of the southeastern Brazilian Atlantic Forest, Phytotaxa 446 (4), pp. 245-252 : 247-249

Peperomia calcicola Marcusso , sp. nov. ( Figs. 2 , 3 )

Type:— BRAZIL. São Paulo, Apiaí, Parque Estadual Turístico do Alto Ribeira ( PETAR), Núcleo Caboclos , início da trilha da pescaria, no paredão após atravessar a caverna, 620 m, 24º25’3.67”S, 48º33’52.89”W, 7 November 2019, G.M. Marcusso et al. 1720 (holotype, HRCB; isotypes MBM, RB, SP) .

Diagnosis:— Peperomia calcicola is characterized by the pilose to pubescent stems and leaves, leaves 7–9-nerved, slightly discolorous, with ovate to large lanceolate, rarely rounded blades with usually acute apex and cordate to rounded base, and spadix of 0.5–1.7 cm long. These features distinguish it from P. adsurgens Yuncker (1966: 179) which shows glabrous stems and leaves, leaves 5–nerved with rounded blades, and spadix of 3–7 cm long and from P. lyman-smithii Yuncker (1966: 147) by the pubescent to glabrescent stem and leaves, leaves 5–7-nerved, rounded to obovate blades with rounded apex, and spadix 10–15 cm long.

Perennial saxicolous herb, 3–10 cm tall. Stem brown, erect-caespitose, 5–7 cm long, pilose to pubescent, internodes 0.2–1.2 cm long, cylindrical. Leaves alternate, petioles 1–4.3 cm long, cylindrical, pilose to pubescent, tomentose in young leaves, vinaceous to green, lamina 0.7–2.7 × 0.7–2.3 cm, ovate, large lanceolate, rarely rounded, apex acute, rarely rounded, base rounded, rarely cordate, margin ciliate, short peltate, 0.1–0.5 cm from the basal margin, 7–9 palmatinerved, pilose to pubescent on both sides, tomentose in young leaves, slightly carnose, chartaceous when dry, whitish green on abaxial side, dark green on adaxial side, brown when dry. Inflorescence spadix erect, simple, terminal and leaf-opposed, peduncle 0.5–1.3 cm long, pilose to pubescent, vinaceous to green, brown when dry, rachis 1–1.7 cm long, glabrous to pilose near the proximal part, green, brown when dry. Floral bract ca. 0.4 mm diam., orbicular, peltate, green. Filaments ca. 4 mm long, white, anthers ca. 0.1 mm long, white, brown when senescent. Ovary ellipsoid, green, stigma apical, fimbriate, white. Fruit not seen.

Additional specimen examined (paratype):— BRAZIL. São Paulo, Apiaí, Parque Estadual Turístico do Alto Ribeira (PETAR), Núcleo Caboclos, trilha Pescaria/Desmoronada, 610 m, 24º25’3.38”S, 48º33’55.47”W, 25 October 2016, P.H.A. Melo et al. 5872 (HRCB 71305).

Phenology:— Flowering from October to December.

Distribution and habitat: ―Known only from the type locality, in Apiaí municipality, São Paulo state, southeastern Brazil. The population recorded is located within the Alto Ribeira State Tourist Park (PETAR), on limestone outcrops in rainforest, in the Atlantic Forest Domain.

Conservation status:— Peperomia calcicola fits in the DD (Data Deficient) category, following the IUCN (2017) categories and criteria, because only one collection locality and one specimen are currently known. However, the single known population occurs in a protected area (PETAR).

Vernacular name:— Without vernacular name.

Etymology:— The specific epithet calcicola refers to the rocky limestone outcrops where this species grows.

Taxonomic notes:— Peperomia calcicola is morphologically close to P. adsurgens Yuncker and P. lyman-smithii Yuncker. It differs from the former by the glabrous stem and leaves, 5-nerved and rounded blades, and from the latter by the pubescent to glabrescent stem and leaves, 5–7-nerved, and usually rounded to obovate blades, with rounded apex. A more detailed comparison is given in Table 1.

Based on the general habit, slender stem with slightly thickened nodes, pubescence, peltate leaves, leaf lamina membranous with palmate venation and simple inflorescences, P. calcicola belongs to the subgenus Multipalmata Scheiris & Frenzke ( Frenzke et al. 2015). This placement agrees with the morphologically close taxa, which belong to the same subgenus, although P. adsurgens has erroneously been assigned to Micropiper (Miq.) Miq. ( Miquel 1843: 45, 76) in Frenzke et al. (2015) (M.S. Samain & L. Frenzke, pers. comm.).

Peperomia specimens examined: — BRAZIL. Peperomia adsurgens : São Paulo: Santo André, Alto da Serra, Estação Biológica, em barrancas húmidas, 22 August 1939, O. Handro s. nº (SP). Peperomia lyman-smithii : São Paulo: Iporanga, PETAR, Núcleo Santana, Bairro da Serra, trilha para o abismo ponta de flecha, 7281292S, 734227W, 550 m, 22 Nov 2005, R. Cielo-Filho et al.450 (SPSF). Rio de Janeiro: Teresópolis, Parque Nacional da Serra dos Órgãos, trilha Mozart Catão, ca. 22º25º- 32’ S, 42º59’ - 43º07W, ca. 1190 m, 14 April 2011, J.A. Lombardi 8419 (HRCB).

Figures

FIGURE 2. Peperomia calcicola. A. Habit erect-caespitose. B. Detail of the abaxial leaf surface, showing the whitish green abaxial side, and dark green adaxial side. C. Detail of the spike showing the rachis green with floral bracts green, withe stamens, and green pistils with white stigma (from G.M. Marcusso et al. 1720; photos by Gabriel Mendes Marcusso).

FIGURE 3. Holotypus of Peperomia calcicola (from G.M. Marcusso et al. 1720, HRCB).