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A Checklist of the Liverworts and Hornworts of North America

1977; American Bryological and Lichenological Society; Volume: 80; Issue: 3 Linguagem: Inglês

10.2307/3242017

1938-4378

Raymond E. Stotler, Barbara Crandall‐Stotler,

Peatlands and Wetlands Ecology

This list includes the species, subspecies and varieties of Hepatics and Anthocerotes reported from the contiguous United States, Canada, Alaska and Greenland. systematic arrangement of the 119 genera found in this area is followed by an alphabetical list of the taxa. This is appended by a catalog of synonyms and excluded names. Essential annotations conclude the checklist. Students of the liverworts and hornworts of North over the past 40 years have relied almost exclusively on the volumes of Frye and Clark (1937-1947) for determination of their collections. Although countless local, state and regional lists, floras and manuals have appeared since 1937-1947, these have, unfortunately, served only as supplementary literature. Thus, the innumerable inaccuracies in Frye and Clark are perpetuated even today. Almost concomitant with the issuance of the first part of Frye and Clark's of North (1937) A preliminary check list of the of Europe and America (Buch et al., 1938) was published. Evans (1940) soon published an expanded American list based upon that compilation along with ideas incorporated from his Classification of the Hepaticae (1939). This enumeration, then, is our most recent checklist, per se, available. Although the later parts of the Frye and Clark work could draw upon both of the previous checklists, the initial number was, of course, mutually exclusive of the Evans' 1939 system. Thus, any attempt to correlate conspecific taxa entered under differing generic or specific names between these two publications has led to undue frustration to the hepatic student. Likewise, the differences in spelling (cf. Trichocolea in Evans versus Tricholea in Frye and Clark) and in countless author citations has thwarted attempts to approach a standardized nomenclature among the numerous bryologists active in North America. Following the completion of the of North thirty years ago (Frye & Clark, 1947), an abundance of floristic additions, confirmations, rejections and synonymizing has transpired. multitude of authors and publications account for these with the efforts of Schuster (1966, 1969, 1974) in his and Anthocerotae of North America, as well as in numerous other papers, contributing 1 The Society is offering a limited number of reprints of this checklist for sale for $2., postpaid. Orders with remittance should be sent to Marshall R. Crosby, Missouri Botanical Garden, 2345 Tower Grove Ave., St. Louis, Missouri 63110. 2 Botany Department, Southern Illinois University, Carbondale, Illinois 62901. This content downloaded from 157.55.39.102 on Mon, 03 Oct 2016 04:19:18 UTC All use subject to http://about.jstor.org/terms 406 THE BRYOLOGIST [Volume 80 the bulk of this information. The unfortunate situation with the Schuster volumes, though, is that they are still far from being completed (he has treated only 12 of the 47 families recognized in this list), and these fail to treat species of the Southwest, the West Coast and the rich flora of the Pacific Northwest. Fortunately, a checklist of British Columbia (Schofield, 1968) has tabulated the numerous additions to the northwestern flora. The intent of this present checklist is multiple. Of greatest urgency is the provision for the user of an alphabetical listing of the genera and species, including subspecies and varieties, of the taxa which have been reported from North America, north of Mexico, and Greenland since the publication of part one of Frye and Clark (1937). Taxa which have since been adequately studied and synonymized, or excluded from the flora, appear in that section of the list. The correct orthography and author citations follow each of the accepted taxa. In many cases this differs from that traditionally employed, which simply indicates the progress made over the past several decades. Such progress has largely relied on the efforts of Grolle (1972, 1976). In the cases of somewhat radical change, annotations are included to explain or document the nomenclature being proposed. The systematic arrangement reflects the authors' divergence from that of Evans (1939) and later systems. This is derived from our thoughts of evolution and phylogeny primarily from a developmental basis. The major departure from current systems is the erection of a discrete division to include the hornworts. Critical developmental and physiological investigations of this group substantiate that these plants are not at all closely related to the Hepatophyta, nor derived from common ancestry (vide Haskell, 1949; Proskauer, 1960). Several suprafamilial groups of liverworts are likewise erected while the other changes are relegated primarily to the sequential arrangement of the families. Several genera or generic complexes have run the gamut of taxonomic possibilities. Certain Jungermannia taxa are placed in the genus Solenostoma by one author while another includes them in Plectocolea. The outstanding, comprehensive study by Vinia (1973-1975), which is followed here, treats a single genus with several subgenera. Likewise, the subfamily Lophozioideae of the Jungermanniaceae may include as few as six or as many as thirteen genera. We have followed the conservative approach here (six genera) as in the case ofJungermannia sensu latu. The proper combinations with those here unrecognized genera are to be found in the synonym list to allow the user to correlate conspecific taxa and utilize the generic appellation of his preference. Taxa between the genus and species level are not incorporated within the checklist. It is hoped that this list will precipitate a standardization of North American liverwort and hornwort nomenclature, and will allow meaningful correlation of floristic works. At the same time, careful study of the various doubtful species reports in our floristic literature should gradually yield to clarification. Many of these will unquestionably be eliminated upon completion of the Schuster flora. We are indebted to Dr. Margaret Fulford for allowing us to utilize her library and for providing us with many invaluable references. Drs. William Steere and G. L. Smith were most accommodating during our study at the New York Botantical Garden. This content downloaded from 157.55.39.102 on Mon, 03 Oct 2016 04:19:18 UTC All use subject to http://about.jstor.org/terms 1977] STOTLER & CRANDALL-STOTLER:LIST OF LIVERWORTS & HORNWORTS 407 SYSTEMATIC ARRANGEMENT OF GENERA DIVISION ANTHOCEROTOPHYTA' CLASS ANTHOCEROTOPSIDA Order Anthocerotales 1. Anthocerotaceae Dum. Anthoceros L. emend. Prosk.