01588nas a2200145   4500008004100000245010900041210006900150260001200219300001200231490000700243520103900250100001801289700001801307856011701325       2006                        eng d00aIsoetes melanopoda spp. silvatica (subsp. nov.), A new quillwort (Isoetaceae) from eastern North America0 aIsoetes melanopoda spp silvatica subsp nov A new quillwort Isoet  c2006///  a15 - 300 v713 aIsoetes melanopoda, a diploid species of ephemeral prairie wetland swales primarily in central North America, has also been found in swamp forests over a wide area of eastern North America in recent years. Determination of certain morphological and ecological characteristics (leaf width, habitat preference, leaf base color, megaspore ornamentation pattern, and megaspore size) distinguishes two population groupings within the species range that maintain discreet geographic distributions and thus represent distinct taxa. Most populations of these two eastern and western taxa are distinctive enough to argue for identification as separate species within I. melanopoda (s.l.). The existence of some apparently intermediate populations within a transition zone between the two taxa and the absence of stand-alone diagnostic identification features, however, indicates that a subspecific level of distinction is more appropriate. Isoetes melanopoda subsp. silvatica, subsp. nov., is proposed for the previously unnamed eastern taxon.1 aBrunton, D.F.1 aBritton, D.M.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-33744742329&partnerID=40&md5=7aca3325d15a4c88962a29a94fd39f25