A taxonomic study of the Carex muhlenbergii and C. cephalophora complexes (Cyperaceae: Phaestoglochin)

Abstract

The seven taxa studied were broken into two complexes based on 49 characters surveyed. In addition, weight was given to achene micromorpholgy in the final placement of taxa into their respective complex. The two complexes are: the C. muhlenbergii complex consisting of C. austrina, C. muhlenbergii var. enervis, and C. muhlenbergii var. muhlenbergii, and the C. cephalophora complex consisting of C. cephalophora, C. leavenworthii, C. mesochorea and a newly described species from Texas and Oklahoma, C. perdentata. Carex mesochorea and C. perdentata have papillose leaves similar to the taxa in the C. muhlenbergii complex. However, the absence of satellites on the surface of the epidermal cells of the achenes removes them from that complex. Type specimens of the previously described taxa were found with the exception of C. muhlenbergii var. muhlenbergii and C. muhlenbergii var. enervis. Carex muhlenbergii var. muhlenbergii is lectotypified. Although the type specimen for C. muhlenbergii var. enervis was not found, it is presumed to be intact. In addition, section Phaestoglochin is typified with Carex muricata. A dichotomous key is provided to separate the taxa of these two complexes. A set of characters was established for comparable diagnoses for the members of the two complexes and will serve to study the other members of section Phaestoglochin and closely allied sections. Achene micromorphology was shown to be valuable characters for separating complexes, species, and varieties. Pollen analyses provided a base line for these two complexes with other members of section Phaestoglochin, but were not shown to be taxonomically signifiant. Taxa of these two complexes range from Texas east to Florida, north to Minnesota and west to Quebec, Canada. Distribution maps of each taxon are also provided.