Eleocharis pedrovianae C.S. Nunes, R. Trevis. & A. Gil, 2016

Nunes, Clebiana De Sá, Gil, André Dos Santos Bragança & Trevisan, Rafael, 2016, Eleocharis pedrovianae, a new species of Cyperaceae from Northern Brazil (Serra dos Carajás, Pará State), Phytotaxa 265 (1), pp. 85-91 : 86-89

Eleocharis pedrovianae C.S. Nunes, R. Trevis. & A. Gil , sp. nov. ( Figs. 1 , 2 C ‒ D )

Type:— BRAZIL. Pará: Parauapebas, Serra dos Carajás , Serra Norte, N 1, 06º01’59” S, 50º16’58” W, 720 m, 28 April 2015, C.S Nunes, P.L. Viana, A. Gil, N.F. O. Mota & A.L. Ilkiu-Borges 35 (holotype: MG!, isotypes: BHCB!, FLOR!, INPA! and RB!).

Apparently annual, submerged, stoloniferous herbs. Stolons 1.4 ‒ 4.5 mm long, green to stramineous. Culms green, partially emergent when fertile (15 ‒ 125 × 0.2 ‒ 0.4 mm) and culms submerged when sterile (ca. 0.5 ‒ 10 × 0.1 mm), longitudinally sulcate when dry, not septate, smooth to slightly striate, capillary, circular in cross section (sometimes sterile ones almost flattened). Sheaths 1 ‒ 3 cm long, the apical third hyaline and membranous, stramineous to greenish, apex oblique, acute, sometimes long apiculate. Spikelets dimorphic; culmless spikelet clustered at the culms tillering zone, submerged, uniflora, 2–3 × 1–2 mm, lanceoloid to ovoid; glumes 4 ‒ 5, spirally arranged, imbricate, rachis absent; lower glumes 2–3, 2–3 × 0.4–0.6 mm, sterile, lanceolate, membranous, stramineous, veined, the keel stramineous, the apex acute to subacuminate, the margins hyaline; upper glumes 2, ca. 2–3 × 0.5 mm, fertile, lanceolate, membranous, stramineous, not veined, the apex acute, the keel green,the sides hyaline; emergent spikelets, on culms apex, multiflorous, 3 ‒ 18 × 3–4 mm, lanceoloid, sometimes narrowly ovoid; glumes 12–14, spirally arranged, loosely imbricate, rachis present; lower glume 1, ca. 1.5–1.8 × 1 mm, sterile, elliptic to lanceolate, membranous, stramineous, veined, the keel green, the apex obtuse, the margin hyaline; upper glumes ca. 1.9–2 × 1.2 mm, fertile, oval to lanceolate, membranous, inconspicuously veined, the apex acute to obtuse, the keel stramineous to green, the sides vinaceous, the margin hyaline. Stamens 2, the anthers ca. 1 mm long; the style trifid ca. 1 mm long. Achene 1 ‒ 1.2 × 0.4–0.5 mm, trigonous, ellipsoid, stramineous, rarely light brown, short-stipitate, 3-costate, reticulate; perianth bristles (4)5, 0.3 ‒ 0.6 mm long, stramineous, retrorsely scabrous; stylopodium pyramidal, the apex acute to acuminate, brown, separated from the achene body by a constriction.

Distribution and Habitat: —This species is known only from the Serra dos Carajás , Pará State, Brazil, in the municipalities of Parauapebas, Serra Norte (N1, N3, N4 and N8), and Canaã dos Carajás , Serra Sul (S11-A and S11-D) ( Fig. 3 ). Eleocharis pedrovianae lives in wetlands, marshes and margins of temporary lakes and lagoons with ferric soil (canga) ( Fig. 2 ). During the rainy season (from January to June) E. pedrovianae is submerged, with only the fertile parts emerging in flood edges of the environments cited above ( Figs. 2 A and D ), and during the dry season (from July to December) is parched above mud forming a dried carpet ( Fig. 2 B ).

Conservation Status: — Eleocharis pedrovianae could be classified according to the criteria of the IUCN Red List (IUCN 2001) as Endangered [EN B2 ab (ii, iv)]. This species is known, so far, only to the region of Serra dos Carajás , with an estimated footprint of 200 km ², which is under intense environmental pressure by mining activity.

Etymology: —The specific epithet for this new species of Eleocharis honors Biologist, Botanist and taxonomist, Dr. Pedro Lage Viana, a researcher of the Museu Paraense Emílio Goeldi, Belém, Pará State, Brazil, creator and coordinator of the project “Rupestral Flora of Serra dos Carajás Revisited ”. He has a deep knowledge of the area’s flora and has strongly encouraged the development of taxonomic studies of Cyperaceae from this important mountain range.

Taxonomic relationships: —This new aquatic species is caracterized mainly by its stoloniferous habit and dimorphic spikelets. One spikelet culmless, clustered at the culms tillering zone, submerged, uniflora, the other spikelets on emergent culms apex, multiflorous. It is similar to two other species of the subs. Chaetariae , Eleocharis angustispicula Trevisan & Boldrini (2010: 505) by being annual, with slender culms, sulcate when dry, the lower glume sterile, floral glumes oval to lanceolate, membranous, apex acute to obtuse, spirally arranged, inconspicuously veined, keel stramineous, with sides vinaceous and hyaline margin, style trifid, stamens 2. It also resembles Eleocharis glauca Boeckeler (1871: 150) , a species described from the state of Pará, which has a semi-aquatic habit and long stolons.

Eleocharis pedrovianae differs from E. angustispicula by being stoloniferous (vs. cespitose), and having (4)5 perianth bristles (vs. rudimentary or absent), ellipsoid achene (vs. obovoid) with reticulate surface (vs. finely puncticulate to reticulate surface), a clearly pyramidal stylopodium, separated from the achene body by a constriction (vs. short pyramidal stylopodium, separate from the achene body by a brief constriction), and dimorphic spikelets present (vs. dimorphic spikelets absent). It differs from E. glauca by presenting (4)5 perianth bristles (vs. perianth bristles rudimentary), achene ellipsoid (vs. achene obovoid-urceoloid) with reticulate surface (vs. cancellate surface), stylopodium clearly pyramidal, separate from the achene body by a constriction (vs. stylopodium short pyramidal, not separate from the achene body by a constriction) and dimorphic spikelets present (vs. dimorphic spikelets absent) ( Table 1).

Additional specimens examined (paratypes):— BRAZIL: Pará: Canaã dos Carajás , Serra dos Carajás , Serra Sul, Corpo D , 6°24’31” S, 50°21’5” W, 820 m, 18 May 2010, M.O.Pivari, L.V.C. Silva & A.O. Santos 1517 (BHCB!); Canaã dos Carajás , Serra dos Carajás , Serra Sul, S 11A, brejo sobre canga-buritizal, 6°20’00” S, 50°27’90” W, 673 m, 21 March 2012, P.B. Meyer, A.J. Arruda, P.L. Viana, F.M. Santos, T.J. Battituci & L.J. Arruda 1140 (BHCB!); Canaã dos Carajás , Serra dos Carajás , Serra Sul, S 11D, campo brejoso alagado, 6°24’28” S, 50°21’5” W, 819 m, 24 April 2012, A.J. Arruda, F.M. Santos, L.J. Arruda & T.J. Battituci 1087 (BHCB!, MG!); Canaã dos Carajás , Serra dos Carajás , Serra Sul, S 11-D, campo brejoso alagado, 6°24’28” S, 50°21’5” W, 819 m, 24 April 2012, A.J. Arruda, F.M. Santos, L.J. Arruda & T.J. Battituci 1091 (BHCB!); Canaã dos Carajás , Serra dos Carajás , Serra Sul, S 11A, campo brejoso alagado, 6°18’11” S, 50°27’41” W, 667 m, 26 April 2012, A.J. Arruda, F.M. Santos, L.J. Arruda & T.J. Battituci 1115 (BHCB!); Parauapebas [Marabá], Serra dos Carajás , Serra Norte , 2 km east of AMZA camp N-1, low wet area on ferric rock outcrops, 6°02’ S, 50°17’ W, 700 m, 25 May 1982, C.R. Sperling, R.S. Secco, M. Condon & A.L. Mesquita 5830 (MG!); [Marabá], Serra dos Carajás , Serra Norte, Lagoa do N4, 14 April 1986, L. Carreira 1056 (MG!); [Marabá], Serra dos Carajás , Serra Norte, Lago do N-1, lago, 17 april 1986, L. Carreira 1070 (MG!); Parauapebas, Serra dos Carajás , Serra Norte, Lagoa do platô N4, vegetação de canga, 15 April 2010, L.C.B. Lobato, L.V. Ferreira, P. Prestes & D. Cunha 3902 (MG!); Parauapebas, Serra dos Carajás , Serra Norte, N 8, brejo com rodeado por campo rupestre sobre canga e campos graminosos, 6°11’80” S, 50°07’56” W, 711 m, 23 March 2012, P.B. Meyer, A.J. Arruda, P.L. Viana, F.M. Santos, T.J. Battituci & L.J. Arruda 1179 (BHCB!); Parauapebas, Serra dos Carajás , Serra Norte, N 1, campo brejoso alagado, 6°00’49” S, 50°17’51” W, 683 m, 19 April 2012, A.J. Arruda, F.M. Santos, L.J. Arruda & T.J. Battituci 911 (BHCB!, MG!); Parauapebas, Serra dos Carajás , Serra Norte, N 1, campo brejoso alagado, 6°01’41” S, 50°17’31” W, 676 m, 22 April 2012, A.J. Arruda, F.M. Santos, L.J. Arruda & T.J. Battituci 1032 (BHCB!); Parauapebas, Serra dos Carajás , Serra Norte, N 1, campo brejoso sobre canga, 6°02’29” S, 50°17’12” W, 684 m, 22 April 2012, A.J. Arruda, F.M. Santos, L.J. Arruda & T.J. Battituci 1047 (BHCB!); Parauapebas, Serra dos Carajás , Serra Norte, N 4-WS, campo graminoso alagado sobre canga, 6°06’36” S, 50°11’11” W, 675 m, 23 April 2012, A.J. Arruda, F.M. Santos, L.J. Arruda & T.J. Battituci 1068 (BHCB!); Parauapebas, Serra dos Carajás , Serra Norte, N 1, coletada na parte mais rasa da lagoa, 6°01’38” S, 50°17’33” W, 28 April 2015, A. Gil, P.L. Viana, C.S. Nunes, N.F. O. Mota & A.L. Ilkiu-Borges 470 (MG!).

Figures

FIGURE 1. Eleocharis pedrovianae, A. Habit. B. Culmless spikelet. C. Sheath apex in dorsal view. D. Sheath apex in ventral view. E. Emergent spikelets, on culms apex. F. Lower sterile glume of emergent spikelets, on culms apex. G. Upper fertile glume of emergent spikelets, on culms apex. H. Achene. I. Achene surface detail. Illustration by João Silveira based on the holotype, C. Nunes et al. 35 (MG).

FIGURE 2. Eleocharis pedrovianae in its natural habitat.A. in the rainy season. B. in the dry season. C. Spikelets in detail. D. habit. C‒D. of the holotype, C. Nunes et al. 35 (MG). (Photos by Pedro Viana).

FIGURE 3. Distribution map of Eleocharis pedrovianae in cangas of Serra dos Carajás. The light grey area represents the Carajás National Forest (FLONA Carajás); red circles, collection sites; black patches, Canga plateaus; dark grey, mining pit.