Selaginella potaroensis Jenman

Valdespino, Ivan A., 2015, Novelties in Selaginella (Selaginellaceae - Lycopodiophyta), with emphasis on Brazilian species, PhytoKeys 57, pp. 93-133 : 110

Selaginella potaroensis Jenman

Selaginella potaroensis Jenman, Gard. Chron., ser. 3, 2: 154. 1887. - Type. Guyana. Essequibo: [ravines near the foot of the] Kaieteur Falls, [04°47' 31.26"N, 58°58'29.21"W], [Sep 1881], G.S. Jenman 1818 (lectotype: NY! [NY00144158], designated by Alston et al. (Bull. Brit. Mus. (Nat. Hist.), Bot. 9: 297. 1981); isolectotypes: BM [BM000634459]-image!, K! [K000589087]).

Additional specimens examined.

COSTA RICA. Heredia: between Río Peje and Río Sardinalito, Atlantic slope of Volcán Barba, 10°17.5'N, 84°04.5'W, 700-750 m, 4 Apr 1986, Grayum 6743 (MO); Parque Nacional Braulio Carrillo, transect between Volcán Barba and OET station La Selva, 600 m, 2003, Kluge 2234 (PMA). BRAZIL. Roraima: Serra dos Surucucus, NE of Mission station, 02°42-47'N, 63°33-36'W, 1000-1400 m, 17 Feb 1969, Prance et al. 9995 (NY).

Discussion.

Selaginella potaroensis was previously known to occur in Venezuela, Guyana, Suriname, and French Guiana ( Alston et al. 1981, Smith 1995, Cremers et al. 2007). Its range is documented here northward to include Costa Rica (see Tropicos 2015b), and it is to be expected in Panama and Colombia. This species is also known from Brazil.

Selaginella potaroensis is a creeping plant characterized by having axillary rhizophores throughout the stems, membranaceous leaves, the median leaves semicordate to ovate with the outer half of the lamina almost twice as wide as the inner one, margins hyaline and denticulate with the outer margin convex and the inner one almost straight, laminae abruptly tapering into a long-acuminate apex with conspicuous stomata on the upper surface, the lateral leaves ovate-elliptic with minute submarginal teeth along the upper surfaces of basiscopic halves, and acute apices tipped by 1-3 teeth. The similarities and differences of Selaginella potaroensis with Selaginella cardiophylla , Selaginella hemicardia , and Selaginella rhodostachya Baker are discussed in Valdespino (1992).