NEOTROPICAL LYCOPODIACEAE - AN OVERVIEW

Approximately 185 species of Lycopodiaceae are known to occur in the Neotropics: ca. 150 belong in the genus Huperzia, ca. 8 in Lycopodium, and ca. 25 in Lycopodiella. The species are enumerated according to assumed relationship, with information of the most important synonyms, a summary of their distribution, comments on their morphology and variability, and reference to selected illustrations. Species delimitation is problematic throughout the family. This is due to the simple morphology and the plasticity of the characters. Morphogenesis seems unstable in many species and may be strongly affected by environmental factors. Most characters are variable within a species, e.g., stem thickness, number of leaf orthostichies, leaf crowding, leaf direction, development of teeth on leaf margins, color, degree of heterophyllous differentiation. Often the diagnostic features of closely related species are without apparent adaptive significance. Hybridization is believed to occur rather freely, but the putative hybrids often have normally developed spores. Three new combinations, Huperzia tubulosa (Maxon) B. Ollg., Huperzia watsoniana (Maxon) B. Ollg., and Lycopodiella torta (L. Underw. & F. Lloyd) B. Ollg., are proposed.