Abstract

Heydrichia homalopasta sp. nov. is described from the east coast of Australia. The new species lacks the prominent pit plug caps found in the two South African species Heydrichia woelkerlingii Townsend, Keats et Chamberlain and Heydrichia groeneri Keats et Chamberlain. In habit, H. homalopasta grows as a thin crust (to 1 mm thick), similar to H. groeneri, but differing from the massive crusts (to 15 mm thick) found in H. woelkerlingii. The tetrasporangial nemathecia of H. homalopasta are single sporangial complexes whereas those of the South African species are composed of numerous sporangial complexes.