Synopsis of the Genus Campylopus in North America North of Mexico

All Campylopus species reported from North America north of Mexico have been critically revised. Campylopus subleucogaster C. Miill. and C. donnellii (Aust.) Lesq. & Jam. are conspecific with C. surinamensis C. Miill. (= C. gracilicaulis Mitt.). Campylopus angustiretis (Aust.) Lesq. & Jam. is newly combined as a variety of C. surinamensis, and C. atrovirens De Not. var. cucullatifolius is described as new. Campylopus aureus Bosch. & Lac. , C. introflexus (Hedw.) Brid. , C. oerstedianus (C. Miill.) Mitt. and C. subulatus Schimp. are reported new to North America. There is discussion of each of the species of Campylopus presently known from North America north of Mexico, including remarks on the taxonomy and distinguishing characteristics. A key to all species is given. There are various, differing opinions on the North American species of Campylopus. Williams (1913) listed nine species; these were Campylopus angustiretis (Aust.) Lesq. & Jam. , C. donnellii (Aust.) Lesq. & Jam. , C. flexuosus (Hedw.) Brid. , C. fragilis (Brid.) B.S.G. , C. gracilicaulis Mitt. , C. introflexus (Hedw.) Brid. , C. schimperi Milde, C. subleucogaster C. Miill. and C. tallulensis Sull. & Lesq. Grout (1936) cited nine species and two varieties, including Campylopus angustiretis, C. atrovirens De Not. , C. carolinae Grout, C. flexuosus, C. fragilis, C. gracilicaulis, C. gracilicaulis var. donnellii, C. introflexus, C. schimperi, C. tallulensis and C. tallulensis var. subleucogaster, but modified his point of view with the remark, that "to the author it seems that flexuosus, tallulensis and subleucogaster belong to the same specific type. " Similarly, the Index Muscorum (Wijk et al. 1959) included (apparent errors aside) eight, but again different species. These are Campylopus angustiretis, C. atrovirens, C. bermudianus Williams in Britt. , C. delicatulus var. carolinae (Grout) Ther. , C. flexuosus, C. fragilis, C. introflexus, C. subulatus and C. subulatus var. schimperi. This latter concept reflected the influence of Bartram (1949), who included Campylopus donnellii, C. gracilicaulis and C. subleucogaster in C. flexuosus. Crum et al. (1973), in their check-list of North American mosses, enumerated eleven species: Campylopus angustiretis, C. arctocarpus (Hornsch.) Mitt. , C. atrovirens, C. carolinae, C. donnellii, C. flexuosus, C. fragilis, C. gracilicaulis, C. introflexus, C. schwarzii Schimp. , C. subulatus and C. subulatus var. schimperi, C. tallulensis is included in C. flexuosus and C. subleucogaster is excluded from the flora. A number of reasons probably account for such variety of concepts. The genus Campylopus is dioicous and sexual dimorphism occurs in several species. This may lead to difficulties if only female plants occur at one locality, or if only female tufts have been collected. Furthermore, some species (e.g., Campylopus surinamensis) have different types of leaves with different areolation along a single stem, for instance, basal leaves forming small rosettes, stem leaves and apical leaves. Also, sterile and fertile plants have 007-2745/80/570-588$2.15/0 This content downloaded from 157.55. 39.184 on Sun, 15 May 2016 05:28:53 UTC All use subject to http://about.jstor. org/terms 1980] FRAHM: CAMPYLOPUS 571 different leaf form and aerolation, especially of the involucral leaves around the perichaetia. The perichaetial leaves are sometimes totally different and, compared with sterile stem leaves, may give the impression of a different species. Finally, as in other genera, the characters are highly variable, not only in plants of different habitats, but also in the same tuft and along the same stem. Therefore, it is necessary to study such features as width of the hyaline border along the leaf base, cell walls, hairpoints, extension of laminae, leaf shape and alar cells on individual plants from numerous populations. In view of the taxonomic problems that can arise with such involved and variable structures, it is not surprising that up to three different annotations may be found on a single specimen. This is exemplified by the lack of consistency in the literature, described above, and clearly indicates the need for a critical revision of the taxa of Campylopus reported for North America. The present study of more than 1000 North American specimens of Campylopus was undertaken to clarify the taxonomic status of the North American species, with the hope that previous experience with the Central and South American species of this difficult genus would be helpful. KEY TO THE TAXA OF Campylopus IN NORTH AMERICA