STUDIES IN CYPERACEAE IN SOUTHERN AFRICA .32. ELEOCHARIS SUBGENUS LIMNOCHLOA SECTION LIMNOCHLOA

A taxonomic treatment of Eleocharis R. Br. subgen. Limnochloa (P. Beau v. ex Lestib.) C.B. Clarke sect. Limnochloa (P. Beauv. ex Lestib.) Ben tham [=ser. Mutatae Svenson] is given for southern Africa. A key is pr ovided for the identification of five species, E. dulcis (Burm.f.) Hen sch., E. acutangula (Roxb.) Schult., E. mutata (L.) Roem. & Schult., E variegata (Poir.) Presl and E. decoriglumis Berhaut. Several of these taxa display a highly variable floral morphology that has been docume nted in the literature without adequate explanation having been given for its occurrence. The speculation is made that within a water body i n which Eleocharis species are sympatic, introgression may be of long standing, the hybrid progeny usually co-existing with the putative par ents so that a wide range of variability may be represented. E. mutata and E. variegata are interpreted as of hybrid origin. E. mutata and E . decoriglumis are recent new records for southern Africa.