EVOLUTION IN SEDGES (CAREX, CYPERACEAE)

Subgenus Primocarex was generally thought to be artificial and derived from diverse multispicate species. Relationships of rachilla-bearing species of subgenus Primocarex, however, were disputed, with some authors suggesting derivation from other genera, and others believing them to be primitive. Subgenus Indocarex was thought to be primitive, with subgenera Carex and Vignea reduced and derived, but occurrence of rachillas is not confined to a few unispicate species, but is widespread. The often suggested connection between Uncinia and unispicate Carex, based on rachilla morphology, is founded on incorrect interpretation of homology. Unispicate Carex without close multispicate relatives probably originated from independent, ancient reductions of primitive, rachilla-bearing, multispicate Carex. The highly compounded inflorescences occurring in subgenus Vignea are hypothesized to represent a primitive state in Carex, and the more specialized inflorescences in subgenus Carex derived from inflorescences of this type. The relationships of subgenus Indocarex remain unclear. -from Author