01188nas a2200241   4500008004100000245007900041210006900120260001200189300001400201490000700215520045700222653001000679653001400689653001500703653001200718653001400730653002700744100001600771700001200787700001700799700001400816856011600830       2002                        eng d00aIsoetes yunguiensis (Isoetaceae), a new basic diploid quillwort from China0 aIsoetes yunguiensis Isoetaceae a new basic diploid quillwort fro  c2002///  a587 - 5910 v123 aIsoetes yunguiensis, a basic diploid species with a chromosome number of 2n = 22, is described and illustrated. This species occurs on the Yunnan-Guizhou Plateau in southwest China. It is similar to I. japonica in its appearance and emergent aquatic habit. Herbarium specimens of I. yunguiensis previously have been misidentified as I. japonica. Isoetes yunguiensis differs from I. japonica in megaspore and microspore morphology and chromosome number.10aChina10aEast Asia10aIsoetaceae10aIsoetes10aQuillwort10aYunnan-Guizhou Plateau1 aWang, Q.-F.1 aLiu, X.1 aTaylor, W.C.1 aHe, Z.-R.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-0036939584&partnerID=40&md5=da8d4d4668c03846b51b3df5877e860202141nas a2200217   4500008004100000245008300041210006900124260001200193300001600205490000700221520145500228653001001683653001701693653001201710653002101722653001401743100001601757700001701773700001601790856011701806       2006                        eng d00aEcology and conservation of the endangered quillwort Isoetes sinensis in China0 aEcology and conservation of the endangered quillwort Isoetes sin  c2006///  a4069 - 40790 v393 aIsoetes sinensis Palmer is an East Asia endemic fern that faces impending extirpation from the expansive area of Mainland China. Presently, only two natural populations are known to exist in this vast region. Both populations have decreased by about 50% within the last 4 years. This reduction is most probably related to the decline in the size of the wetlands since reproductive activity, spore production, and recruitment were noticeably lower at the microsites occurring in smaller ponds. The decline in population size seems to be associated with succession from marsh to dry land at the habitats of both populations. The study revealed that individuals in both populations produced copious numbers of spores suggesting adequate fecundity, furthermore high levels of spore germination were obtained in laboratory experiments. However, inefficient spore dispersal appears to have contributed to the limited spread of the species. The sex ratio in both populations was male-biased. Several factors are identified here as posing a threat to Isoetes sinensis populations in China, chiefly the loss of habitat due to infrastructure construction and competition with adventive weed species for establishment on available sites. Disturbance by introduced mammals during browsing and trampling by livestock farm workers, as well as tourists, further contribute to the diminishing numbers of Isoetes sinensis at the study sites. © 2005 Taylor & Francis.10aChina10aConservation10aEcology10aIsoetes sinensis10aRare fern1 aWang, J.-Y.1 aGituru, R.W.1 aWang, Q.-F.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-33646483501&partnerID=40&md5=91677e55ca7f81da659db6f0f6afe26002208nas 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