No abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. This content downloaded from 150.131.192.151 on Sun, 05 Apr 2015 12:49:50 UTC All use subject to JSTOR Terms and Conditions Abstract. The checklist includes a listing of the genera and species of North American mosses thought to occur in the continental United States and Canada. The floras of Mexico and Greenland are not included. The list for Sphagnum is in an accompanying paper. Including Sphagnum, 1,320 species and 109 varieties are recognized in 312 genera and 72 families. Accompanying the list are a systematic arrangement of the genera, species, and varieties, and a list ofsynonyms and excluded species. Three nomenclatural changes are made: Limprichtia cossonii (Schimp.), comb. nov., Polytrichum papillatum (G. L. Sm.), comb. nov., and Schistidium heterophyllum (Kindb. in Mac. & Kindb.) McIntosh, comb. nov. The first comprehensive checklist of the mosses of North America north of Mexico was published by Grout (1940), with Andrews (1940) providing a list of Sphagnum species. In 1965, Crum, Steere, and Anderson produced their first checklist which was revised eight years later (Crum et al. 1973). The same three authors began a second revision of the list several years ago, but the effort was interrupted by pressures of other tasks. Shortly thereafter, Bill Steere regrettably withdrew from the project. Several years later Crum and Anderson resumed work on the list. William R. Buck's involvement dates back to his graduate student days at the University of Michigan.Through the years, especially recently, he has contributed enormously to all aspects of the checklist. The senior authors feel that his efforts fully justify their invitation to become a joint author. Thus, with the help of many bryologists throughout the world we present here the long overdue revision.The systematic arrangement of the genera and families, more or less, follows the sequence of Brotherus (1924)(1925). We have shifted several genera and we have made minor rearrangements of families. The current trend in bryology seems to be toward narrower generic and familial concepts, and we have more or less followed this trend. For those who disagree with our usage we have provided the authorities for names listed among the synonyms. The users of the checklist therefore can easily retrieve whatever names they wish.It is next to impossible to construct a checklist that is entirely updated and error free. It is also impossible to make one that will please anyone, even ourselves. Species are unequal in value, even in the same genus, and opinions concerning their limits vary enormously. Notions about generic lim-It is with respect and affection that we dedicate this checklist to our late friend and colleague, William C. St...

Summary Based on correlated gametophytic and sporophytic characteristics, 57 families of pleurocarpous mosses are classified in four orders. Four new families are recognized. Five families are segregated into a new suborder of the Bryales, the Rhizogoniineae. The remaining 52 families are arranged in three orders. Suborders and superfamilies are used to reflect the proposed phytogeny. A standardized ending for superfamilies, ‐acanae, is proposed. Each family is discussed, light microscope and scanning electron micrographs are provided to illustrate salient structural features, and cladograms are presented to summarize the classification.

No abstract

Taxonomic groups and ecoregions shape the “lenses” through which biodiversity is assessed and conserved. A historical bias toward vertebrates and vascular plants in the northern hemisphere underpins how global patterns of biodiversity in terrestrial ecosystems are perceived. Here, we focus on the hitherto overlooked non‐vascular flora (liverworts and mosses) in the remote sub‐Antarctic Magellanic ecoregion of southwestern South America. We report that: (1) this ecoregion hosts outstanding non‐vascular floristic richness, with > 5% of the world's bryophytes on < 0.01 % of the Earth's land surface; (2) species richness patterns for vascular and non‐vascular plants are inverted across 25 degrees of latitude in Chile; and (3) while vascular plants are 20 times more abundant than non‐vascular plants globally and in tropical South America, non‐vascular plants are dominant in the sub‐Antarctic Magellanic ecoregion and Antarctic Peninsula. These findings have been translated into policy and conservation decisions, including the creation of the Cape Horn Biosphere Reserve in 2005 and the introduction there of “tourism with a hand lens” in the diverse “miniature forests” of bryophytes, lichens, and invertebrates. We argue for consideration of ecoregional‐ or biome‐specific indicator groups, rather than a narrow set of global indicator groups, for designing effective conservation strategies.

No abstract

Pleurocarpous mosses, characterized by lateral female gametangia and highly branched, interwoven stems, comprise three orders and some 5000 species, or almost half of all moss diversity. Recent phylogenetic analyses resolve the Ptychomniales as sister to the Hypnales plus Hookeriales. Species richness is highly asymmetric with approximately 100 Ptychomniales, 750 Hookeriales, and 4400 Hypnales. Chloroplast DNA (cpDNA) sequences were obtained to compare partitioning of molecular diversity among the orders with estimates of species richness, and to test the hypothesis that either the Hookeriales or Hypnales underwent a period (or periods) of exceptionally rapid diversification. Levels of biodiversity were quantified using explicitly historical "phylogenetic diversity" and non-historical estimates of standing sequence diversity. Diversification rates were visualized using lineage-through-time (LTT) plots, and statistical tests of alternative diversification models were performed using the methods of Paradis (1997). The effects of incomplete sampling on the shape of LTT plots and performance of statistical tests were investigated using simulated phylogenies with incomplete sampling. Despite a much larger number of accepted species, the Hypnales contain lower levels of (cpDNA) biodiversity than their sister group, the Hookeriales, based on all molecular measures. Simulations confirm previous results that incomplete sampling yields diversification patterns that appear to reflect a decreasing rate through time, even when the true phylogenies were simulated with constant rates. Comparisons between simulated results and empirical data indicate that a constant rate of diversification cannot be rejected for the Hookeriales. The Hypnales, however, appear to have undergone a period of exceptionally rapid diversification for the earliest 20% of their history.

No abstract