Tomentypnum falcifolium Ren. ex Nich.
Curved-leaved golden moss
Tomentypnum nitens var. falcifolium, Camptothecium nitens var. falcifolium, Homalothecium nitens var. falcifolium
Basis for Former Listing
Tomenthypnum falcifolium was first discovered in the state by G. A. Wheeler in 1977 (Wheeler and Glaser 1982) and it was listed as a special concern species in Minnesota in 1984. Intensive peatland research since then has turned up numerous additional occurrences (Janssens 2010), with nearly as many records as its common putative ancestor, the rich fen species T. nitens (Vitt and Hamilton 1975). It has recently been reported from the Lake Baikal area in Siberia, Inner Mongolia, and far northeast China (Vitt et al. 1990), thus extending its range to circumboreal.
Basis for Delisting
The numerous additional discoveries and the extensive range of T. falcifolium in the Laurentian Mixed Forest Province in northern Minnesota have indicated that this moss is much more common and widespread than originally thought to be. Therefore, T. falcifolium was delisted in 2013.
Tomenthypnum falcifolium is branched like a feather or fern leaf, with the branches decreasing in length along both sides of the stem (5-10 cm; 2.0-3.9 in.) toward the top. The highly glossy plants with yellow-gold color and dark brown tomentum (a dense layer of hairlike rhizoids covering the stem and the bases of several of the leaves) are diagnostic, as are the sickle-shaped, longitudinally wrinkled (plicate) leaves (Crum and Anderson 1981; Faubert 2004). The leaf cells are strongly elongate in contrast to the macroscopically (superficially) similar Aulacomnium palustre, which is also found on the dry tops of Sphagnum spp. (peat moss) hummocks. The capsules of T. falcifolium are not diagnostic. Other species that are similar but lack the distinctive tomentum are Sanionia uncinata and Ptilium crista-castrensis, both of which occur in quite different habitats.
In contrast to the extreme rich fen species T. nitens, T. falcifolium is found in less minerotrophic peatlands. It is nearly always associated with Sphagnum spp. and can be found as scattered stems on tall Sphagnum spp. hummocks in fens and swamps with circumneutral minerotrophy.
Biology / Life History
Tomenthypnum falcifolium is a perennial species with a pleurocarpous (freely branched) growth habit. However, because it is frequently tightly packed among fast-growing Sphagnum spp. plants, the main stems often grow upright and the branches usually lag behind in development or do not develop at all. Because of the dark-brown tomentum and the tendency of the leaves to curve to one side, the stems often take on the appearance of Aulacomnium palustre, another common moss of Sphagnum spp. hummocks.
Conservation / Management
Its extensive range, common availability of microhabitat and peatland type, and the numerous recent findings suggest that T. falcifolium is not as rare as once thought. It is likely that T. falcifolium went unrecognized for a long time until the publication of the paper by Vitt & Hamilton (1975).
Conservation Efforts in Minnesota
No known conservation efforts have been directed towards this species to date.
References and Additional Information
Crum, H. A., and L. E. Anderson. 1981. Mosses of eastern North America. 2 volumes. Columbia University Press, New York, Yew York. 1330 pp.
Faubert, J. 2004. Tomentypnum. Bryophyte Flora of North America, Provisional Publication.
Hedenas, L. 1987. On the taxonomic position of Tomenthypnum Loeske. Journal of Bryology 14:729-736.
Janssens, J. A. 2009. MS Access database on Minnesota bryophytes. Lambda-Max Ecological Research, Minneapolis, Minnesota.
Minnesota Department of Natural Resources. 2012. Statement of need and reasonableness. Minnesota Department of Natural Resources. Division of Ecological and Water Resources. St. Paul, Minnesota. 337 pp.
Vitt, D. H., and C. D. Hamilton. 1975. Taxonomic status of Tomenthypnum falcifolium. The Bryologist 78:168-177.
Vitt, D. H., T. Cao, M. K. Campenot, and R. Gauthier. 1990. The genus Tomenthypnum in north-east China. Journal of Bryology 16:79-87.
Wheeler, G. A., and P. H. Glaser. 1982. Tomenthypnum falcifolium in Minnesota. The Michigan Botanist 21:66.