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/22601046nas a2200121   4500008004100000245008200041210006900123300001100192490000800203520065100211100001800862856004400880       2015                        eng d00aKey to the Quillworts (Isoetes: Isoetaceae) of the Southeastern United States0 aKey to the Quillworts Isoetes Isoetaceae of the Southeastern Uni  a86-1000 v1053 aAn illustrated key based on morphological, ecological and geographical characteristics is presented for the Isoetes taxa of the Coastal Plain, Piedmont and the eastern side of the Appalachian Mountains of Alabama, District of Columbia, Delaware, southern Maryland, North Carolina, South Carolina, Florida, Georgia, Mississippi, eastern Louisiana, southeastern Tennessee and eastern Virginia. The key includes 22 species, three additional subspecies/ varieties and nine sterile hybrids. It is primarily intended to serve as an investigative tool to assist field botanists engaged in conservation, floristic and ecological studies in the Southeast.1 aBrunton, D.F.  uhttps://isoetes.myspecies.info/node/21801006nas a2200145   4500008004100000245013500041210006900176300001200245490000800257520049600265100002000761700001700781700001800798856004400816       2015                        eng d00aIsoetes in Kamchatka (northern Russian Far East), with the Description of a New Hybrid I. x paratunica (I. asiatica x I. maritima)0 aIsoetes in Kamchatka northern Russian Far East with the Descript  a101-1120 v1053 aTwo species of Isoetes (Isoetaceae) occur in the Kamchatka Peninsula, northern Russian Far East — I. asiatica (Makino) Makino and I. maritima Underw. The distribution and ecology of these species are discussed. A hybrid of these species was found alongside its parental species in south Kamchatka in the shallows of a lake impacted by humans, and it is formally described here as I. x paratunica D. F. Brunton, Mochalova & A. A. Bobrov. It is the first Isoetes hybrid discovered in Russia.1 aMochalova, O.A.1 aBobrov, A.A.1 aBrunton, D.F.  uhttps://isoetes.myspecies.info/node/217