Eleocharis pseudobulbosa T. Lima, A. Gil and R. Trevisan, 2014

Eleocharis pseudobulbosa T. Lima, A. Gil and R. Trevisan View in CoL , sp. nov. ( Fig. 1 View FIGURE 1 )

Type: — BRAZIL. São Paulo: mun. Capão Bonito, rodovia de acesso ao Bairro dos Lemes, a 2.9 km do término do perímetro urbano. Propriedade Santo Antonio, da família Almeida , 23º59’58.36”S, 48º23’24.33”W, ca. 683 m, 5 July 2010, T. Lima, A. Gil & D. Barros 109 (holotype FLOR! GoogleMaps , isotype FCB! GoogleMaps ).

Perennial, caespitose-stoloniferous herbs. Stolons ca. 0.5–65 mm × 0.5 mm, with straw-colored scales, forming a bulb-like structure in the growing points of the new culms. Culms 10–120 × 0.5–0.7 mm, almost circular to oval in cross section, capillary, longitudinally sulcate when dry, not septate. Sheaths 5–20 × 0.5–1 mm, straw-colored to light brown, apex oblique, acute, sometimes with a short apiculum. Spikelets 3–6 × 0.5–2.5 mm, predominantly reddish-brown, elliptical to slightly ovoid, 10–25(–30)-flowered, not proliferous, glumes spirally arranged; lower (basal) glume 1–3 × 0.5–1 mm, sterile, persistent, enclosing ca. 2/3 of spikelet base, oval, apex rounded to slightly emarginated, midrib inconspicuous, keel ocher and conspicuous, continuous with the culms, verging by a reddishbrown macula, with hyaline margin ca. 0.3–0.5 mm wide; floral glumes 1–2.5 × 0.5–1.3 mm, boat-shaped with a narrow midrib, ocher to green, sides reddish-brown, with hyaline margin ca. 0.3–0.5 mm wide and emarginated apex. Flowers without perianth bristles or sometimes with their vestiges; stamens 3, filaments lamellar, brown in the base, hyaline in apex, anthers ca. 1-1.1 mm, yellow, ending in a short brown apiculum; style trifid and brown. Achene 0.6 × 0.4 mm, trigonous, 3-costate, 3-convex, obovoid, white to cream, surface with thin series of longitudinal cells, shortly stipitate; stylopodium 0.3 × 0.4 mm, as wide as the achene, pyramidal, brown to lightbrown.

Distribution and Habitat: —This species is known only from type locality (Capão Bonito, Southern São Paulo state, Brazil), where it grows in the border of an open temporary swamp surrounded by wheat and soybeans plantation, next to an Atlantic Forest fragment ( Fig. 2 View FIGURE 2 ).

Etymology: —The epithet for this species is Latin for “false bulb”, in reference to its bulb-like structures composed by the scales in the region of stolons from which new branches emerge.

Phenology: —a lot of mature flowers and a few numbers of mature fruits have been collected in July (only type specimens were observed).

Taxonomic relationships: —The new species is morphologically similar to Eleocharis densicaespitosa Trevisan & Boldrini (2010: 505) and Eleocharis quinquangularis Boeckeler (1888: 15) , sharing the caespitose habit, the slender culms, the oblique sheath apex without hyaline appendix, the sterile lower (basal) glume with a wide hyaline margin, the floral glumes always with brownish parts, the absence of perianth bristles, the 3 stamens and trifid styles, the trigonous, obovoid achene and the pyramidal stylopodium. Eleocharis pseudobulbosa differs from both species by the presence of conspicuous stolons (vs. rhizomes), circular to oval culms in cross section (vs. 5-angled), spikelets with smaller number of flowers [10–25(–30)] [vs. 40–70(–180) in E. densicaespitosa and 40 in E. quinquangularis ], smaller (0.6 mm long) and slightly reticulate achene (vs. 1–1.2 mm long in E. densicaespitosa and 0.8 mm long in E. quinquangularis and both smooth) and stylopodium as wide as the achene (vs. ca. 3/ 4 in E. densicaespitosa and ca. 1/3 to 2/ 3 in E. quinquangularis ). Furthermore, E. pseudobulbosa can be easily confused with Eleocharis filiculmis Kunth (1837: 144) , differing in absence of perianth bristles (vs. 4–5 in E. filiculmis ), by having stolons (vs. rhizomes in E. filiculmis ) and by presence of only one sterile lower glume (vs. 2 in E. filiculmis ).