eMonocot Cyperaceae

an authoritative resource for Cyperaceae data worldwide, integrating global and regional perspectives

Taxonomy of the Carex straminea complex (Cyperaceae)

Publication Type:Journal Article
Year of Publication:1997
Authors:Rothrock, P. E., Reznicek, A. A., Ganion L. R.
Journal:Canadian Journal of Botany-Revue Canadienne De Botanique
Keywords:biogeography, Carex, Cyperaceae, hybrid, section ovales, sem, taxonomy

The Carer straminea complex (section Ovales) consists of five species limited to hydric communities of eastern North America. Based upon gross morphology and perigynium structure, these species are closely aligned with the Carer albolutescens complex but not the western species Carex Seta. An SEM investigation of the micromorphology of achene and style epidermis from 15 species of Carer section Ovales demonstrated much interspecific variation. As a result, these data could not confirm the relationship between the C. straminea complex and the C. albolutescens complex but did support the delimitation of section Ovales. Numerical analysis showed that characters of the inflorescence and perigynium are satisfactory for separating C. straminea from Carer hormathodes, a species limited to the Atlantic coast. Likewise, characters of inflorescence, pistillate scale, and perigynium could clearly separate the geographically widespread Carer alata from the Florida endemic species Carer vexans. A fifth and relatively distinctive species, Carer suberecta, was found to have a narrow ecological preference for fens and a distribution limited to the upper Midwest, with outlying populations in western Virginia. Putative natural hybrids are documented between Carer scoparia and Carer longii and some species in the C. straminea complex.

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