AMPHICARPY IN THE CYPERACEAE, WITH NOVEL VARIATION IN THE WETLAND SEDGE ELEOCHARIS-CAESPITOSISSIMA BAKER

Amphicarpy, the heterocarpic production of serial and basal fruits, oc curs in the Cyperaceae in species of the primarily mesophytic genera B ulbostylis and Trianoptiles and in species of the helophytic genera El eocharis and Schoenoplectus. There is a variety of breeding systems an d growth forms across these amphicarpic species. Eleocharis caespitosi ssima is amphicarpic, with basal fruits buried by positively geotropic culms. The seeds of basal fruits in this species may arise asexually. The selective pressures likely to be important in the development of amphicarpy in the Cyperaceae are discussed.