Lycopodium

• Authority

  Mickel, John T. & Beitel, Joseph M. 1988. Pteridophyte Flora of Oaxaca, Mexico. Mem. New York Bot. Gard. 46: 1-580.

• Family

  Lycopodiaceae

• Scientific Name

  Lycopodium L.

• Description

  Genus Description - Plants epiphytic or terrestrial; stems erect, pendent, or trailing, sparsely to highly branched; leaves abundant, small, simple, needle- or awl-shaped, 1-veined, generally spirally arranged, rarely slightly dimorphic in four ranks, sporangia in the axils of normal vegetative leaves or specialized leaves of a terminal strobilus, strobili sessile or pedunculate; sporangia unilocular, 2-valved, reniform or globose, spores isomorphic, tetrahedral-globose; gametophytes surficial or subterranean, green or non-green, fleshy or tuberous.

• Discussion

  Type species: Lycopodium clavatum Linnaeus. Huperzia Bemhardi, J. Bot. (Schrader) 1800(2): 126. 1801. Urostachys Herter, Beih. Bot. Centralbl. 39(2): 249. 1922, nom. superfl. Type: Huperzia selago (Linnaeus) Schrank & Martius [=Lycopodium selago Linnaeus]. Lycopodiella Holub, Preslia 36: 22. 1964. Type: Lycopodiella inundata (Linnaeus) Holub [=Lycopodium inundatum Linnaeus]. Palhinhaea Carvalho e Vasconcellos & Franco, Bull. Soc. Broten II, 41: 24. 1967. Type: Palhinhaea cernua (Linnaeus) Carvalho e Vasconcellos & Franco [=Lycopodium cernuum Linnaeus]. Diphasiastrum Holub, Preslia 47: 104. 1975. Type: Diphasiastrum complanatum (Linnaeus) Holub [=Lycopodium complanatum Linnaeus]. Lycopodium is a cosmopolitan genus of about 400 species, mostly of the wet tropics in middle to higher elevations and with several temperate species. There are 16 species in Oaxaca, of which ten are broadly distributed. Some workers divide Lycopodium into several genera, showing various lines of evidence, including chromosome number, that distinguish these groups. Diversity in morphology and chromosome number is frequent in other ancient genera, such as Lindsaea, Dennstaedtia, Hypolepis, Gleichenia, and the senior author prefers to take a conservative (lumping) view of these genera. The junior author believes that the differences in basic morphological features (such as spores, stele, roots, chromosome number, etc.) as well as biological features (such as type of gametophytes, phenology of sporophytes, habitats, and hybrid behavior) correlate into three groups that should be recognized as the following genera: Lycopodium s. medio (L. clavatum and L. thyoides in Oaxaca), Lycopodiella Holub (L. cernuum in Oaxaca), and Huperzia Bernhardi (all the other species in Oaxaca). References: Beitel, J. 1979. Clubmosses (Lycopodium) in North America. Fiddlehead Forum 6(5): 18; Hersey, R. E. & D. M. Britton. 1981. A cytological study of three species and a hybrid taxon of Lycopodium (section Complanata) in Ontario. Cañad. J. Genet. Cytol. 23: 497-504; Nessel, H. 1939. Die Bärlappgewächse (Lycopodiaceae). Gustav Fischer, Jena. 404 pages; 011gaard, B. 1975. Studies in Lycopodiaceae. I. Observations on the structure of the sporangium wall. Amer. Fern J. 65: 19-27; 011gaard, B. 1979. Studies in Lycopodiaceae, II. The branching patterns and infrageneric groups of Lycopodium sensu lato. Amer. Fem J. 69: 49-61; 011gaard, B. 1983. Lycopodiaceae. In Stolze, R., Ferns and fern allies of Guatemala, Part III. Fieldiana, Bot. n.s. 12: 20-44; Takamiya, M. & R. Tanaka. 1982. Polyploid cytotypes and their habitat preferences in Lycopodium clavatum. Bot. Mag. (Tokyo) 95: 419-434; Tanaka, R. & M. Takamiya. 1981. Polyploidy in Lycopodium clavatum of Japan. Chromosome Inform. Serv. 31: 5-6; Underwood L. M. & F. E. Lloyd. 1906. The species of Lycopodium of the American tropics. Bull. Torrey Bot. Club 33: 101-124; Wagner, F. S. 1980. Chromosome behavior in three interspecific hybrids of Diphasiastrum (Lycopodiaceae). Bot. Soc. Amer. Misc. Ser. Publ. 158: 121-122; Wilce, J. 1972. Lycopod spores. I. General spore patterns and the generic segregates of Lycopodium. Amer. Fem J. 62: 65-79.