Eleocharis reznicekii (cyperaceae), a new species from the mexican high plateau

Abstract

Eleocharis reznicekii (Cyperaceae, subg. Eleocharis, series Eleocharis), is described and illustrated. It is morphologically intermediate between E. densa and two species of Eleocharis subseries Eleocharis (E. macrostachya and E. palustris). The new species differs in a combination of characters including conspicuously compressed culms (3 to over 5 times wider than thick) and stylopodium sessile on a thin annular base. Eleocharis reznicekii differs additionally from E. densa by having relatively lax spikelets, mostly bifid styles, and achenes almost smooth at 30x. From E. macrostachya and E. palustris it is distinguished in its oblong to linear-oblong spikelets, the proximal floral scale clasping only 1/3 to slightly more than 1/2 of the culm, and the proximal plus 1-2(3) subproximal scales without a flower. Eleocharis reznicekii is known only from the state of Durango, in the Mexican high plateau and piedmont of the Sierra Madre Occidental.

Caracterización de los cariotipos de ocho especies mexicanas de Eleocharis (Cyperaceae)

“…Interspecifi c hybridization may be a widely overlooked evolutionary phenomenon in Eleocharis and may have a signifi cant role in its diversifi cation (Košnar et al, 2010). Karyological data in the present study do not support the hypothesis of the hybrid origin of E. reznicekii suggested by González-Elizondo et al (2007). At least, no intermediate chromosome numbers were found between the putative parents, as in Bureš (1998) studies.…”

“…In this study, E. reznicekii and one of its putative parents (E. densa) are 2n = 16, whereas E. macrostachya and E. xyridiformis (that also were suggested as putative parents) are both 2n = 28. To test the hybrid origin hypothesis, molecular and/or cytogenetical analyses are required (González-Elizondo et al, 2007). Because of the perennial mat-forming habit, long, horizontal rhizomes; mostly bifi d styles; and biconvex, blunt angled, yellow to brown achenes almost smooth at 30x, E. reznicekii is classifi ed into Eleocharis subg.…”

Cyperaceae in Mexico: Diversity and distribution

“…Additional references for the family in Mexico include descriptions of new taxa (e.g., Reznicek 1982, 1990b, González-Elizondo 1985, Tucker 1982, Cochrane 1981, Kral & Thomas 1986, Reznicek & González-Elizondo 1995, 1997, 1999, 2001a, Roalson 1999, Strong & González-Elizondo 2000, Ramos-Álvarez & Diego-Pérez 2002, 2007a, 2009, Rosen 2009, Saarela et al 2010, Gómez-Sánchez et al 2012, LeBlond et al 2015; data on taxonomy or distribution (González-Elizondo & Rzedowski 1983, 1984, Strong 1993, González-Elizondo & Peterson 1997, Diego-Pérez et al 2001, González-Elizondo & Tena-Flores 2000, González-Elizondo et al 2002, 2007b, Reznicek & González-Elizondo 2008, Rosen et al 2007, 2008a,b, Herbario CICY 2010, and uses or bioprospecting of sedges for pharmacology or phytoremediation (Flores-Tavizón et al 2005, López-Martínez et al 2008, Pérez-López et al 2009.…”