Cyclosorus

Abstract: The objective of this study reported here was to characterize arsenic (As) accumulation by Pteris ferns by comparing 3 of the ferns of this genus with each other as well as with four non-Pteris ferns growing on seven sites in southern China with different As levels. A total of 112 samples, including 78 Pteris vittata, 13 P. cretica, 3 P. multifida and 18 ferns from other non-Pteris genera, with the soils in which they grew were collected for As and other elemental analyses. P. vittata was found to be the most dominant species and the most efficient As-accumulator, whereas P. multifida was the lowest As-accumulator among the Pteris ferns, with 4.54-3599, 28.7-757 and 11.2-341 mg kg(-1) As recorded in the fronds of P. vittata, P. cretica and P. multifida, respectively. Arsenic concentrations in non-Pteris ferns were generally much lower than those in Pteris ferns, with 0.81-1.32, 3.59, 10.7, 6.17-24.3 mg kg(-1) in the fronds of Blechumum orientale, Dicranopteris dichotoma, Pteridium aquilinum and Cyclosorus acuminatus, respectively. For P. vittata, the As bioaccumulation factor (ratio of As in fronds to that in soils) changed, whereas the As translocation factor (ratio of As in fronds to that in roots) remained unchanged among the different sites. The concentrations of Fe were very high in all of the collected fern sample, with the exception of B. orientale, with 207-6865, 637-3369, 375-1856, 1876, 493-6865 and 492 mg kg(-1) in the fronds of P. vittata, P. cretica, P. multifida, C. acuminatus, P. aquilinum and D. dichotoma, respectively. The association between Fe accumulation and As accumulation and tolerance in these ferns indicates the unique role of Fe in As-hyperaccumulation.

Abstract: Christella Lev. emend. Holttum sect. Christella is described and discussed, with a key to all known species, synonymy and description for each. New species described are: C. adenopelta, C. kumaunica, C. minima, C. nana, C. pacifica, C. subdentata, & C. timorensis, also the new variety C. harveyi (Mett.) Holttum var. connivens. 2 1 new combinations are made. The following doubtful names may possibly apply to species of this genus: Polystichum consanguineum Gaud., Nephrodium dicarpum Fee, N. griffithianum F&e, & Aspidium natalense Fee. Cyclosorus jerdonii Ching, included in a list of species of Christella in 1971, is here excluded.

Abstract: The Micronesia-Polynesia bioregion is recognized as a global biodiversity hotspot. However, until now estimates regarding the number of endemic plant species for the region were not supported by any comprehensive published work for the region. The results of this study indicate that Micronesia has the world's highest percentage of plant endemism per square kilometer out of all globally recognized insular biodiversity hotspots. A checklist of all endemic plant species for Micronesia is presented here with their corresponding geographical limits within the region. A summary of previous work and estimates is also provided noting the degree of taxonomic progress in the past several decades. A total of 364 vascular plant species are considered endemic to Micronesia, most of them being restricted to the Caroline Islands with a large percentage restricted to Palau. The checklist includes seven new combinations, one new name, and two unverified names that require additional study to verify endemic status. Overviews of each respective botanical family represented in the list are given including additional information on the Micronesian taxa. Recommendations for future work and potential projects are alluded to throughout the text highlighting major data gaps and very poorly known taxa. The following new combinations and names are made: Cyclosorus carolinensis (Hosokawa) Lorence, comb. nov. , Cyclosorusgretheri (W. H. Wagner) Lorence, comb. nov., Cyclosorusguamensis (Holttum) Lorence, comb. nov., Cyclosorus palauensis (Hosokawa) Lorence, comb. nov. , Cyclosorus rupiinsularis (Fosberg) Lorence, comb. nov., Dalbergia hosokawae (Hosokawa) Costion nom. nov., Syzygium trukensis (Hosokawa) Costion & E. Lucas comb. nov..