A new combination in Lycopodiella (Lycopodiaceae)

摘要

Lycopodium L. sensu lato is currently considered to contain several distinct elements best treated as genera. Evidence for recognition of these segregate genera is provided by sporophyte, gametophyte, and spore morphology, anatomy, analysis of chromosome numbers, and phytochemicals (Bruce 1976; Ollgaard 1987; Pedersen and Ollgaard 1982; Towers and Maass 1965; Wagner and Beitel 1993). Lycopodiella Holub is a small group of wetland species with elongate horizontal shoots, unbranched upright shoots, apically leaf-like sporophylls, and photosynthetic gametophytes. A new combination is proposed for this genus. Richard J. Eaton began a series of collections in 1928 of an unusual bog clubmoss from Concord, Massachusetts. The new Lycopodiella was robust with upright shoots commonly 14-17 cm tall. The margins of both'the leaves and the sporophylls were toothed. The horizontal shoots were noteworthy in that they arched above the substrate. The strobilus represented a large proportion of the total upright shoot height (25-53 percent). Eaton (1931) noted that over a period of several years the colony increased in size. Using available evidence--unique combination of morphological characters and persistence of the colony--Eaton provided the new bog clubmoss with the name Lycopodium inundatum L. var. robustum R. J. Eaton (he used the genus Lycopodium because Lycopodiella was not held generically distinct at that time). Eaton probably chose to ally the new plant with Lycopodium inundatum on the basis of the relatively tall strobilus.