A new species and two new records of the fern genus Cheilanthes (Pteridaceae) from Southwestern Brazil.

ABSTRACT.--Cheilanthes pantanalensis, a new species from the Brazilian Pantanal is described. A complete morphological description is presented, as well as illustrations and comments on the most similar species. This species is distinguished by its (2-)3-pinnate leaves and by having ultimate segments that are ovate to suborbicular. We also report Cheilanthes hassleri and C. obducta as new records for Brazil, both from Mato Grosso do Sul.

KEY WORDS.--Cheilanthes, Pteridaceae, new species, Pantanal, Brazil

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The genus Cheilanthes includes about 150 species, most of them occurring in semixeric, rocky places of tropical regions. In the Neotropics, the genus has about 100 species, some 50 of which are found in South America. The semixeric regions of Central Brazil, northern Argentina, Paraguay, and eastern Bolivia are especially important for the diversity of the genus, and contain several endemic species (Ponce et al., in press).

As currently defined, the genus appears to be polyphyletic, but further phylogenetic and monographic studies are needed to better understand the delimitation of natural groups (Smith et al., 2006; Prado et al., 2007; Schuettpelz et al., 2007). The genus can be defined by the scaly rhizomes short- to long-creeping, fronds 1-5-pinnate, hairy and/or scaly, veins flee, and by the sori near the margins of the segments that are enrolled and differentiated (Mickel and Smith, 2004).

For the Neotropics, a significant number of species have been treated in regional floras, such as Tryon and Stolze (1989), Rodriguez (1995), Sota (1977), Sota et al. (1998), Ponce (1984), and Prado (1992, 2004). An exhaustive checklist for the southern South American species is presented by Ponce et al. (2008) in the "Catalogo de las Plantas Vasculares del Cono Sur", with 27 species recorded for this region.

Recent collections from the Brazilian Pantanal and a small portion of the northeastern Chaco region, close to the borders to Paraguay and Bolivia, have provided new information on the diversity and distribution in Cheilanthes, revealing a new species and two new records that are here presented.

Cheilanthes pantanalensis E. Assis, Ponce & Labiak, sp. nov. TYPE.--BRAZIL. Mato Grosso do Sul: Corumba, Serra do Amolar, Morro do Sucuri, 700 m, 18 Oct. 2002, E. Assis et al. 364 (HOLOTYPE: UPCB; ISOTYPES: COR, SI, SP). Fig. 1 A-E and Fig. 2 A-B.

Filix monticola quae in saxis viget. Species haec C. obductae Kuhn affinis, sed laminis tripinnatis, segmentis ovatis vel suborbiculatis ab ea recedit.

Rhizomes suberect to short-creeping, 3-6 mm diam., scaly, the scales linear-lanceolate, 2.5-3.5 mm long, concolorous, reddish-brown, with filiform or furcate-filiform apices, margins entire to faintly dentate at the base; fronds monomorphic, 4-22 cm long; stipes 0.5-2.5 cm long, dark brown to atropurpureous, terete, moderately to densely hairy, the hairs articulated, each cell with an elongate acicular appendage, whitish; blades 3-pinnate, lanceolate, 3.5-19.5 cm long, 2-4 cm wide, subcoriaceous, adaxially with scarce, filiform hairs (sometimes glabrescent), abaxially densely hairy, the hairs ca. 5-7 mm long, multicellular, uniseriate, each cell with an elongate acicular appendage that points away from the apex of the hair, the articulations between cells with a "tongue in groove" connection; rachises and costae dark brown, with hairs similar to those on the laminar tissue; pinnae deltate-lanceolate to ellipticallanceolate, 1-2 cm long, 0.3-0.9 cm wide, ascending ca. 70[degrees]-80[degrees] to the rachises, short-stipitate, apices pinnatifid; pinnules deltate, 1.5-4.5 mm long, 1-2 mm wide, subsessile, apices often trilobate; ultimate segments ovate to suborbicular, 2-4 pairs, contiguous, apices roundish, bases subcordate, subsessile, margins entire; veins flee, 2-furcate; sori at the ends of the veinlets, each covered by a slightly enrolled lobule, pauci-sporangiate; sporangia glabrous; spores tetrahedral, shallowly echinate, 32 per sporangium.

DISTRIBUTION AND HABITAT.--Known only form the type locality, where it grows on rocks in open places, about 700 meters in elevation.

ETYMOLOGY.--The specific epithet refers to the geographic area where this species was found--the Pantanal.

Cheilanthes pantanalensis can be recognized by its (2)3-pinnate blades, densely covered by multicellular and uniseriate hairs on the abaxial surface. The hairs are typical, with each cell bearing an elongate acicular appendage that points away from the apex of the hair, and with the articulations between cells with a "tongue in groove" connection (Fig. 1, D). Its ultimate segments are ovate to suborbicular. This species is most similar to Cheilanthes obducta Mett. ex Kuhn, and shares with this species the typical laminar hairs (Fig. 2, E) and shallowly echinate spores (Fig. 2, F). However, C. obducta exhibits 2pinnate blades (Fig. 1, G), with lanceolate to deltate-lanceolate ultimate segments, while in C. pantanalensis these are ovate to suborbicular (Fig. 1, H). Its distribution overlaps with that of the two species now reported in Brazil.

Among the other species that occur in the Chaco and the Pantanal regions, Cheilanthes myriophylla Desv. and C. hassleri (Weath.) Ponce are most similar. They both differ by having true scales on the laminar tissue.

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

New Records:

Cheilanthes hassleri (Weath.) Ponce, Darwiniana 45: 240. 2007.

Notholaena hassleri Weath., Lilloa 6: 274, t. 4. 1941. TYPE.--PARAGUAY, "In regione calcarea cursus superioris fluminis Apa", Hassler 10996 (HOLOTYPE: K!; ISOTYPES: P!, MO, NY!).

DESCRIPTION AND ILLUSTRAT1ON.--Tryon (1956).

DISTRIBUTION AND HABITAT.--Previously known only from Paraguay, and now recorded from the western border of Brazil. This fern grows on calcareous sediments alongside rivers.

SPECIMENS EXAMINED.--BRAZIL. Mato Grosso do Sul: Mun. Bonito, Logradouro, Fazenda Remanso, 20[degrees]53'38" S; 56[degrees]44'58" W, 410 m, 12 Dec 2005, G.A. Damasceno Jr. et al. 4196 (COR, SI).

DISCUSSION.--This rare species can be recognized by its lamina that is densely scaly on the abaxial surface and scarcely hairy on the adaxial surface. The hairs are uniseriate, short-celled, catenate (Fig. 2, C), and whitish or translucent. These features are unique among the other species of Cheilanthes in southern South America. Its cristate spores (Fig. 2, D) are typical and can be found in many cheilanthoids ferns.

Cheilanthes obducta Mett. ex Kuhn, Linnaea 36: 83. 1869. TYPE.--BOLIVIA. La Laguna (now Padilla): D'Orbigny 386 (Isotype: P!).

Notholaena balansae Baker, J. Bot. n. ser. 7: 301. 1878. TYPE.--PARAGUAY. Asuncion: Rio Paraguay, IV/1874, Balansa 330 (Holotype: K!; Isotypes: G!, BM!, P!).

DESCRIPTION AND ILLUSTRATION.--Tryon (1956); de la Sota (1977).

DISTRIBUTION AND ECOLOGY.--Venezuela, Colombia, Ecuador, Peru, Paraguay, Argentina, Bolivia; now recorded from Brazil (west border). Epipetric in open and semixeric environments.

SPECIMENS EXAMINED.--BRAZIL. Mato Grosso do Suh Corumba, Morro Santa Cruz, estrada para a Mineracao Corumbaense S.A., 19[degrees]24'49,5" S and 59[degrees]22'47" W, 5 Jul 2005, E. Assis et al. 574 (UPCB, COR, SI); Ladario, Estrada Parque-Bancada Lateritica, 19[degrees]10'02" S and 57[degrees]33'31" W, 25 Jul 2001, E. Assis & G. A. Damasceno Jr. 280 (UPCB, COR, SI); Rod. Campo Grande a Aquidauana, km 110, Faz. Ledao, 14 Dec 1976, G.J. Shepherd et al. 4079 (MBM).

DISCUSSION.--This species can be recognized by its 2-pinnate blades, that are conspicuously hairy abaxially. The hairs are multicellular, uniseriate, with each cell bearing an elongate acicular appendage that points away from the apex of the hair, and the articulations between cells with a "tongue in groove" connection (Figs. 1, F; 2, E).

ACKNOWLEDGMENTS

We thank Francisco Rojas for preparing the illustrations; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (GAPES) for providing the Master's scholarship for the second author; and the COR staff, who helped in the field expeditions.

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M. MONIGA PONCE

Instituto de Botanica Darwinion, Labarden 200, C. C. 22, B1642HYD San Isidro, Argentina, e-mail: [e-mail]

ELTON LUIS MONTEIRO DE ASSIS

Universidade Federal do Parana Curso de Pos-graduacao em Botanica. Caixa Postal 19031, 81531-980, Curitiba, PR, Brasil

PAULO HENRIQUE LABIAK

Universidade Federal do Parana. Departamento de Botanica, Caixa Postal 19031, 81531-980, Curitiba, PR, Brasil, e-mail: [e-mail]