L. Hedenäs
Sarmentypnum Tuomikoski & T. J. Koponen
Plants medium-sized to rather large, green, yellow-green, brownish, red-brown or with clear red colors. Stem sparsely to richly radially branched; with central strand and without or sometimes with a partial exterior hyalodermis, cells within cortex thin-walled; paraphyllia absent; rhizoids smooth, slightly branched, rhizoids or rhizoid initials at various points on the leaves, or on scattered points or in rows on the stem; axillary hairs with 1--7 distal hyaline cells or these early becoming brown. Stem leaves straight or falcate, triangular to ovate or narrowly ovate, either gradually narrowed to a longly acuminate, acuminate or obtuse apex, or suddenly narrowed to a shortly acuminate to broadly rounded and usually apiculate apex, not or indistinctly plicate, concave or strongly concave; margin plane, entire, sinuous or denticulate; costa single, ending ca. 60% distally in leaf to longly excurrent; median lamina cells linear, incrassate or thin-walled, porose or not, smooth; alar cells quadrate or shortly to longly rectangular, hyaline and thin-walled, or (especially near costa or when old) red or brown and incrassate, inflated or strongly inflated, in transversely triangular, narrowly transversely triangular or almost quadrate group, distinctly or indistinctly delimited from surrounding cells, not or hardly decurrent or (W. tundrae) longly and broadly decurrent. Branch leaves smaller and sometimes narrower than stem leaves. Sexual condition autoicous or dioicous. Interior perichaetial leaves gradually or ± suddenly narrowed to longly or shortly acuminate apex, not plicate; margin unbordered, ± entire or with an occasional tooth at shoulder; costa single, ending in lower acumen to longly excurrent; lamina cells smooth; vaginula naked. Seta reddish. Capsule cylindric, curved, horizontal; with no separating annulus; operculum conic. Peristome perfect; exostome reticulate on exterior base, margin dentate distally. Spores (11.0--)12.5--31.0 µm, finely papillose.
Species ca 10 (7 in the flora): widespread.
The genus Warnstorfia consists of species with leaves either gradually curved to straight and gradually narrowed to the apex, or straight and suddenly narrowed to a usually apiculate apex. Red colors frequently occur in several species, and the leaves are non-decurrent in all species except W. tundrae. The alar groups are transversely triangular, or in W. pseudostraminea mostly isodiametric, and consist of inflated, and (at least when young) usually hyaline cells. Except for W. tundrae, Warnstorfia species typically occur in intermediately mineral-rich to mineral-poor fens, W. fluitans sometimes also in bogs. Most species are found in nutrient-poor habitats. However, W. tundrae grows in somewhat nutrient-rich places, and W. fluitans, natural habitats of which are mostly poor or very poor in nutrients, can stand considerable nutrient-enrichment as evidenced by polluted localities in Europe.
Warnstorfia tundrae shares no apomorphic traits with the other species in Warnstorfia or with those in Calliergon, two possible genera for this species. It is here included in Warnstorfia, where several species of similar habit occur. Warnstorfia plants with falcate leaves and lacking sporophytes or red pigments are frequently confused with falcate-leafed species with transversely triangular alar groups in the Drepanocladus aduncus relationship. However, the frequently present rhizoid initials found close to leaf apices in all such Warnstorfia species except W. trichophylla (in which they are rare) are very helpful in differentiating these from the Drepanocladus species, which always lack such initials. In addition, Warnstorfia species are in general radially branched, the leaves generally give an "ordered" impression when viewing the entire plants, and the distal portion of the axillary hairs frequently consist of more than two cells. These Drepanocladus species are distichously branched, their leaves give a more unordered impression, and their axillary hairs have almost invariably only one or two distal cells, except D. polygamus, which has 1--3 distal cells. When sporophytes are present, the numerous sporophytic and perichaetial characters mentioned in the introduction to the family make the separation of these taxa easy.
Species likely to occur in North America
Warnstorfia procera (Renauld & Arnell) Tuomikoski (Drepanocladus procerus (Renauld & Arnell) Warnstorf), is widespread and rather common in the Boreal Zone of northern Europe, but is still unknown from North America. It is usually strongly red or blackish red, has strongly concave and in distal portion furrowed leaves, entire or almost entire leaf margins, and lacks the partial hyalodermis that is present in the two closely related species W. exannulata and W. pseudosarmentosa. Warnstorfia procera occurs in slightly more mineral-poor habitats than the latter two, often in flarks.
SELECTED REFERENCES
Hedenäs, L. 1993. A generic revision of the Warnstorfia-Calliergon group. J. Bryol. 17: 447--479. Janssens, J. A. 1983. Past and extant distribution of Drepanocladus in North America, with notes on the differentiation of fossil fragments. J. Hattori Bot. Lab. 54: 251--298. Wynne, F. E. 1944. Studies in Drepanocladus. IV. Taxonomy. Bryologist 47: 147--189. Wynne, F. E. 1945. Studies in Calliergon and related genera. Bryologist 48: 131--155.
OTHER REFERENCES
Ireland, R. R., Brassard, G. R., Schofield, W. B. & Vitt, D. H. 1987. Checklist of the mosses of Canada II. Lindbergia 13: 1--62.
Mogensen, G. 1995. Warnstorfia trichophylla (Warnst.) Tuom. et T. Kop., a bryophyte new to Greenland (Musci, Amblystegiaceae). Lindbergia 20: 3--4.
Version 1: November, 1999
Version 2: November, 2000-- illustrations added
