Calamagrostis pisinna Swallen, Contr. U.S. Natl. Herb. 29(6): 257-258. 1948[1949].

Sylvester, Steven P., Soreng, Robert J., Bravo-Pedraza, William J., Cuta-Alarcon, Lia E., Giraldo-Canas, Diego, Aguilar-Cano, Jose & Peterson, Paul M., 2019, Paramo Calamagrostis s. l. (Poaceae): An updated list and key to the species known or likely to occur in paramos of NW South America and southern Central America including two new species, one new variety and five new records for Colombia, PhytoKeys 122, pp. 29-78 : 29

Calamagrostis pisinna Swallen, Contr. U.S. Natl. Herb. 29(6): 257-258. 1948[1949]. Fig. 5E, F

Type.

Venezuela. Mérida: rocky ridges, higher paramos, near El Gavilon, 4200 m alt., 25 Jan. 1929, H. Pittier 13277-1/2 (lectotype, designated here: US (US00149283! [A-two flowering culms are the type, B-on left side of sheet is unknown])).

Comments.

Previously considered endemic to Venezuela ( Escalona 1988a) but specimens have been found in the Sierra Nevada del Cocuy of the Cordillera Oriental of Colombia. Specimen Sylvester 3107 differed slightly from the species described from Venezuela in that the leaf blades were densely pilose and often found to be conduplicate (Fig. 5E, F ). As only one flowering specimen was encountered of this morphotype and specimens being found growing out of fairly inaccessible crag ledges, more collections need to be made to ascertain whether this may be a distinct species. All specimens from the Sierra Nevada del Cocuy have a rachilla extension with hairs that reach or surpass the apex of the floret, while Venezuelan specimens have rachilla hairs which usually do not surpass the apex of the palea ( Escalona 1988a). Saarela et al. (2017) found one of the specimens of C. pisinna that we cite here (Cleef 8653) to have an unusual placement in plastid analyses (no nuclear ribosomal data was obtained) as a basally diverging lineage in a moderately to strongly supported clade that also contained Lagurus ovatus L., Aveninae s.str., and Koeleriinae excluding L. ovatus . However, there is a phylogenetic discrepancy between matK and PsbK sequences reported by Saarela et al. (2017) for C. pisinna that needs to be evaluated before any taxonomic conclusions can be drawn.

There is a sterile tuft on the left side of the Pittier type sheet that is a different species and quite possibly a different genus, having acicular involute blades and longer acute ligules that are decurrent (p.p. b). Thus, we lectotypify to the two flowering tufts on the right side of the type sheet (p.p. a), which are identical and fit the description in the type protologue.

Specimens examined.

COLOMBIA. Boyacá: Mun. Chiscas, páramo de Chacaritas, limit between páramo and superpáramo, growing out of rock ledge, 6°37.6794'N; 72°23.6616'W, 4072 m alt., 4 Mar. 2018, S.P. Sylvester, R.J. Soreng, W. Bravo & L.E. Cuta 3107 (US); Sierra Nevada del Cocuy, Páramo Cóncavo, Cueva de los Hombres, 3 km N del Morro Púlpito del Diablo, 4350 m alt., 28 Feb. 1973, A. Cleef 8610 (US-01234789); 4350 m alt., A. Cleef 8653 (US-01234736).

Figures

Figure 5. A general habit and a spikelet of Calamagrostis guamanensis Escalona, J. R. I. Wood 4064 (FMB), Calamagrostis heterophylla (Wedd.) Pilg., S. P. Sylvester 3158 (US), Calamagrostis pisinna Swallen, S. P. Sylvester 3107 (US), and Calamagrostis rigida (Kunth) Trin. ex Steud., S. P. Sylvester 3125 (US). Habit scale bar 5 cm; spikelet scale bar 1 mm.