01542nas a2200145   4500008004100000245007100041210007000112300001200182490000800194520109600202100001801298700001901316700001701335856004401352       2015                        eng d00aStudies on chromosome numbers and spore size in Brazilian Isoëtes0 aStudies on chromosome numbers and spore size in Brazilian Isoëte  a226-2370 v1053 aThe lycophyte genus Isoëtes L. is nearly cosmopolitan, with approximately 350 species, 23 of which occur in Brazil. The lack of adequate distinguishing morphological characters in the leaves and stems, as well as the frequent cases of hybridization and polyploidy, makes the identification of species very difficult. Usually the spores provide the best characters for distinguishing species within Isoëtes, but these can vary in size because of polyploidy and hybridization. In this work we studied the variation in size of both mega- and microspores, and the relationship between size and ploidy level. We also present the first chromosome counts for seven species that are endemic to Brazil: I. goebelii (2n  =  33), I. martii (2n  =  44), I. maxima (2n  =  22), I. organensis (2n  =  66), I. ramboi (2n  =  44) I. smithii (2n  =  44), and I. spannagelii (2n  =  22). Our results suggest a correlation between ploidy level and spore size can be useful for the establishment of a preliminary hypothesis on polyploidy and hybridization among Brazilian Isoëtes.1 aPereira, J.B.1 aMittelbach, M.1 aLabiak, P.H.  uhttps://isoetes.myspecies.info/node/22601363nas a2200133   4500008004100000245009100041210006900132300001200201490000700213520085500220100002001075700001701095856011701112       2013                        eng d00aA new species of Isoetes with tuberculate spores from southeastern Brazil (Isoetaceae)0 anew species of Isoetes with tuberculate spores from southeastern  a869-8740 v383 aIsoetes quiririensis is described, illustrated, and compared to similar species. This species can be distinguished from other species in Brazil by a set of characters that include microphylls that are semi-cylindrical in cross section, velum covering more than 3/4 of the sporangium, tuberculate megaspores varying from 477-670 μm in diameter, echinate microspores, and a chromosome number of 2n = 22. We also include a key for species from the Atlantic Rainforest that have tuberculate megaspores, distribution maps, and spore images for all species that are discussed. Isoetes quiriensis is known only from the type locality, where it occurs as an aquatic in small streams at high elevations. We suggest it should be classified as a data deficient species based on the IUCN criteria. © Copyright 2013 by the American Society of Plant Taxonomists.1 aPereira, J.B.S.1 aLabiak, P.H.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-84892771709&partnerID=40&md5=5330336025d70b7769a8178a24b91c8d01131nas a2200229   4500008004100000245006300041210006200104260001200166300001400178490000800192520043100200653001900631653001400650653001500664653001500679653001300694100001800707700001900725700002300744700001700767856011700784       2012                        eng d00aIsoetes mourabaptistae, a new species from Southern Brazil0 aIsoetes mourabaptistae a new species from Southern Brazil  c2012///  a174 - 1800 v1023 aIsoetes mourabaptistae, a new species from southern Brazil, is described, illustrated, and compared to the most similar species. This new species is apparently restricted to southern Brazil, and is characterized by cristate to irregularly reticulate megaspores and microechinate microspores. It is an aquatic plant, occurring among submersed rocks along rivers, at about 9001100 m in elevation. © 2012, American Fern Society.10aaquatic plants10adiversity10aIsoetaceae10alycophytes10ataxonomy1 aPereira, J.B.1 aWindisch, P.G.1 aLorscheitter, M.L.1 aLabiak, P.H.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-84868016532&partnerID=40&md5=d3bc8e1e27c5d582b331a37819fb1514