02070nas a2200205   4500008004100000245011200041210006900153260001200222300001400234490000700248520138100255653001401636653001401650653001201664653002001676653001101696653002501707100001601732856011601748       1998                        eng d00aStudies on Annalepis from Middle Triassic along the Yangtze river and its bearing on the origin of Isoëtes0 aStudies on Annalepis from Middle Triassic along the Yangtze rive  c1998///  a768 - 7740 v403 aSpecimens of Annalepis have been found from the Middle Triassic Series in the Yangtze River valley and described, including a new species. Annalepis is similar to the living plant, Isoëtes , in many aspects, such as the herb with a corm, more or less clustering sporophylls, presence of a ligule, monolete suture microspores of Aratrisporites -type and trilete megaspores, etc. The similarities of features between the two plants indicate their close affinities and that A . brevicystis might be the ancestry of Isoëtes . Since there is a ligule on the sporophyll of Pleuromeia, the Pleuromeiaceae represented by Pleuromeia could be allied to the Isoëtaceae, and both families should belong to Isoëtales. Isoëtales represents a distinct evolutionary sequence and is inferred as being evolved probably from Palaeozoic Sigillaria . In Mesozoic age, two evolutionary lines are proposed: one as a line from Pleuromeia to Nathorstiana in relation to wood-monopolar rhizophore; the other as a line from Annalenis to Isoëtes related to herb-bipolar corm. Annalepis appeared almost simultaneously in the Yangtze River valley in early Middle Triassic, but the distribution of Annalepis was concentrated from east to west during middle-late Middle Triassic, in relation to the marine regression which occurred cyclically from east to west on the Yangtze Platform during that time.10aAnnalepis10aEvolution10aIsoetes10aMiddle Triassic10aOrigin10aYangtze river valley1 aMeng, F.-S.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-0032414084&partnerID=40&md5=b6306b3189c6672809b1bab17e2dd16802208nas a2200217   4500008004100000245005800041210005600099260001200155300001400167490000700181520157700188653001001765653001401775653001201789653001101801653002101812100001201833700001201845700001601857856011701873       2008                        eng d00aSpore morphology of Isoëtes (isoëtaceae) from China0 aSpore morphology of Isoëtes isoëtaceae from China  c2008///  a479 - 4890 v463 aMicromorphological characters of mega- and microspores of five Isoëtes species from China were observed under scanning electron microscope (SEM). Megaspores of I. hypsophila have a levigate ornamentation, and are 358 μm in diameter (mean, n=30), microspores of this species have a gyrus ornamentation, and are 22 μm in length (mean, n=30); megaspores of I. yunguiensis have a cristate-reticulate ornamentation, with a size of 390 μm in diameter (mean, n=30), while microspores nearly smooth with some fine granulates, and with a size of 22 gm in length (mean, n=30); megaspores of I. taiwanensis are tuberculate and 312 μm in diameter (mean, n=30), echinate microspores are 24 μm in length (mean, n=30); cristate megaspores of I. sinensis are 409 μm in diameter (mean, n=30), and echinate microspores are 28 μm in length (mean, n=30); megaspores of I. orientalis have a cristate-reticulate ornamentation, with diameter of 420 μm (mean, n=30), microspores of this species have an echinate-tuberculate ornamentation with a size of 34 μm in length (mean, n=30). Based on the morphological characters of spores and chromosome numbers among taxa, it was found that mean spore size in each species of Isoëtes generally reflected the ploidy level. I. hypsophila, I. yunguiensis and I. taiwanensis, with smaller mean spore size, are diploidy with 2n=22; I. sinensis (2n=44) and I. orientalis (2n=66), with larger mean spore size, are polyploidy. The spore morphology of Isoëtes still plays an important role in identification and classification of Isoëtes from China.10aChina10aEvolution10aIsoetes10aOrigin10aSpore morphology1 aLiu, X.1 aLiu, H.1 aWang, Q.-F.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-57349117891&partnerID=40&md5=f310ff0165e440259efb4b7c64314743