Table Of Content

New mourabaptistae, from Isoetes a Species Southern Brazil Paulo Windisch G. eral do Rio Grande do Sul, Depto. de Botanies, CP. Alegre, RS, Brazil, e-mail: [email protected] Maria Lorscheitter L. do Rio Grande do de eral Sul, Institute Biociencias, 1 Paulo H. Labiak* do Parana, Depto. de Botanica, CP. 19031, 81531- •al The genus Isoetes L. comprises approximately 350 species (Hickey et al, most them and 2003), of occurring as aquatic plants in lakes streams, but also on permanent wet The genus widely as terrestrials or seasonally soils. is dis- many tributed around the world, but of species tend have very narrow to its distributions (Hickey, 1986; Hickey 2003; Small and Hickey, 2001; et al., Luebke and Budke, Choi 2003; et 2008). al., Hickey (1990) considered South America to be a center of both morpholog- and taxonomic However, one ical diversity for Isoetes. this of the less is still known and regions, published estimates of the diversity of Isoetes in South Two America vary considerably. of the most important contributions South to American provided by Fucks-Eckert and Hickey Isoetes, (1982) (1985), suggest, much respectively, between 75 and 47 species for this region. Undoubtedly work needed South America. to assess the actual diversity in In Brazil is still known particularly, Isoetes one of the less groups of lycophytes, and most of is the species are represented by a very limited number of collections. Prado and Sylvestre (2010) recorded 14 species for Brazil (12 endemics), most of them NEW A FROM PEREIRA ETAL.: ISOETES BRAZIL distributed along the coastal mountains of the southeastern and southern regions. A study on the spore morphology of ferns and lycophytes of Rio Grande do Sul (Lorscheitter et 2009), and additional fieldwork conducted by the al., new we authors, has identified the presence of a species of Isoetes that describe herein. Isoetes mourabaptistae Windisch, M. and B. S. Pereira, P. G. L. Lorscheitter, ]. TYPE.— Labiak, sp. nov. Brazil. Rio Grande do Sul, Sao Francisco de Paula, PACA Rio Tainhas, 1 Oct. 2005, P. G. Windisch 10056 (Holotype: 107431). A-B; A-D; A-D. Figs. 1 2 3 quam cm minus Cormus Plantae parvae, 15 altae. erectus, bilobatus. Radices synchronae, dichotome conspicue 10- divisae, succulentae. Folia chartacea, cm 6-11 20- ascendentia, longa. Alae castaneae, apice vulgo truncatae, 35, 25% per foliae longitudinem ascendentes. Subula olivacea, ascendens, apice Squamae Labium Velum attenuata. absentes. absens. Ligula deltato-lanceolata. incompletum. Sporangium hyalinum. Megasporae basale ellipticum, albae, 558-736 hemisphaero triletae, |im diametro, distali reticulato vel cristato, hemisphaerio proximali reticulato. Microsporae monoletae, microechinatae, 24-31 13-22 |im longae, |um latae. cm among Plants submerged, growing rocks in streams, less than 15 tall. mm Corm 3-10 bilobed, wide. Roots synchronous, dichotomous. erect, mm cm Microphylls 10-35, ascending, chartaceous, 6-11 4-6 linear, long, mm wide and wide at the base 1-2.5 in the medial portion, base of the mm cm microphylls wide alate, the alae 1.4-2.3 long, 0.5-0.8 (above the 20-25% sporangium), extending the length of the microphyll, castaneous, apices often truncate. Subula olive green, ascending, semiterete, the apex Labium membrana- atenuate. Scales absent. absent. Ligule deltate-lanceolate, mm mm and Velum ceous, 2.2-2.5 long 1.4-1.8 wide. incomplete, covering 50-75% 25-50% of the sporangium width, and of the sporangium length. mm mm Sporangium basal, elliptic, hyaline, 3.1-3.4 long, 1.9-2.4 wide. Megaspores whitish, trilete, globose in equatorial view, globose to subtrian- = gular in proximal view, 558-736 (x 669) |im wide, irregularly reticulate to densely cristate distally, irregularly reticulate proximally. Microspores gray, = = monolete, elliptic, 30-38 (x 34) [im long, 23-28 [x 25) fim wide, perispore — Additional Specimens Examined. Brazil. Rio Grande do Sul: Sao Jose dos Bueno Ausentes, Silveira, 09 Dez. 1994, R. 4471 (ICN). Etymology.—The Moura specific epithet honors Dr. Luis Rios de Baptista, botanist from the Federal University in Porto Alegre, Rio Grande do Sul. — known Distribution and Ecology. Isoetes mourabaptistae from only two is collections: one from Sao Francisco de Paula, and the other from Sao Jose dos Ausentes, both in the northeastern part of Rio Grande do Sul. was found It Fig. 1. A-B. A. Habit of Isoetes mourabaptistae. B. Velum (the arrow indicates the edge of the velum with the fenestra below). Scale bars: A = 2 cm and B = 1 mm. (All from the Holotype, P. G. growing submerged, on rocks in shallow, clear waters, altitudes of about at 900-1100 m. Taxonomic Notes.—According Hickey to et al. (2009), in the southern part of South America there is a group of species with reticulate megaspores that is complex very taxonomically. This group includes species such as /. brasiliensis H. P. Fuchs, ekmanii U. Weber, fuscomarginata H. Fuchs, P. /. /. A NEW FROM PEREIRA ETAL: ISOETES BRAZIL 178 AMERICAN FERN JOURNAL: VOLUME NUMBER 102 2 (2012) view of a microspore. D. Detail of the outer coating showing the microechinate" surface. E. /. sehnemii [Sehnem PACA), 17094, equatorial view. F. /. spannagelii [Pereira et al. 626, UPCB), microechinate microspores. megaspores most In contrast, the of of the species ^m from southern Brazil are usually than 400 and less in diameter, the microspores always have smooth outer coatings. cm In the size of the microphylls (up to 11 long) and habit (Fig. A), Isoetes 1 mourabaptistae resembles sehnemii Fuchs and H. P. spannagelii H. /. /. P. Fuchs. However, the megaspores of sehnemii are much smaller (332-^80 /. NEW PEREIRA ETAL: A ISOETES FROM BRAZIL (-554) |am diam.) and the microspores smooth 2E and are (Figs. 3E]. In /. nm spannagelii the megaspores are 406-562(-603) in diameter and distinctly and The consistently reticulate. microspores are also smooth 2F and (Figs. 3F). Hans made Peter Fucks-Eckert labeled a collection by Luis Rios Moura- Baptista as 'Isoetes batistae' [Moura-Baptista 7719, PACA), and also cited this name on pages 237 and 256 of his work published in 1982 (Fucks-Eckert, 1982). However, Fucks-Eckert never validly published new name this nomen PACA (therefore a nudum). The specimen the Herbarium very at is depauperate, with only fragments of the microphylls. Even though was it same and collected in the river, likely represents the species described here, we cannot be sure about its identity given the absence of the characters that distinguish this species from congeners. its — known Conservation Status. Isoetes mourabaptistae currently from only is two from two collections, different rivers in southern Brazil. This suggests that it is locally rare and has a narrow distribution, therefore deserving special attention relative to its conservation status. However, based on our current knowledge of population and geographic and its size distribution, according to lUCN Red (lUCN, List Criteria 2001), assessed here as Data Deficient (DD). it is mk UFPR" the "Centra de Microscopia Eletronica da and Tremarin Priscila Izabel SEM We the images. also thank Dr. Thelma Veiga Ludwig and Dr. William Rodi 1 able help in this work. This study is part of Jovani Souzas Master Dissertatio possible through a fellowship from CAPES. Paulo Labiak, Paulo Windisch, and tter are Research Grant recipients from the Brazilian Research Council (CNPq). AMERICAN FERN VOLUME NUMBER JOURNAL: 102 2 (2012)