Observations onFosliella farinosa(Lamour.) Howe (Rhodophyta, Corallinaceae) in the British Isles

Abstract

A description of Fosliella farinosa is given based on material collected in the British Isles between May 1975 and April 1977. Using field material and crusts cultured from uninucleate bispores the development and seasonal variation of the vegetative thallus and the trichocytes which it bears are discussed. The seasonal occurrence of the tetrasporangial, gametangial and bisporangial conceptacles is recorded. The previously little known bisporangial conceptacles are described in greater detail as is a sterile conceptacle form which develops in winter. Culture studies which have established the bisporangial life-history are reported. An account is given of the ecology of this species and finally the conflicting views of the delimitation of the genera Fosliella and Heteroderma are discussed.