SPORE MORPHOLOGY OF ANEMIA,MOHRIA, AND CERATOPTERIS (FILICALES)

Spores of the ferns Anemia and Mohria (Schizaeaceae) and Ceratopteris (Pteridaceae) are surveyed with light microscopy and scanning and transmission electron microscopy. In each genus the spores are trilete with radially symmetrical exine sculpture comprising three sets of parallel or near-parallel muri. Anemia has six spore types. One is reticulate (A. wrightii-type), and the other five types have either cicatricose or canaliculate sculpture that reflect a basic form, i.e., three mural sets that have mutual anastomoses in each radial region. The cicatricose A. mexicana- and the canaliculate A. dregeana-types represent the simplest expressions of this pattern. Specializations include cicatricose, auriculate (A. raddiana-type) and canaliculate, ornate (A. oblongifolia-, A. phyllitidis-types). Exine structure is homogeneous or differentially microporate; the enveloping two-layered perine has granulate structure and a granulate to spiculate and/or pitted surface. Mohria spores have a stratified, granulate to rugulose perine and cicatricose exine sculpturing consistent with the A. mexicana-type pattern, but the muri are hollow. The canaliculate spores of Ceratopteris differ from those of Anemia and Mohria in that the three mural sets are discrete and separated from each other by a stria in each radial region; exine structure is homogeneous and the thin perine is granulate. Within Anemia the A. raddiana-type is exclusive to subgen. Coptophyllum and the A. oblongifolia- and A. phyllitidis-types to subgen. Anemia. Three spore types are shared by two subgenera; i.e., A. wrightii- and A. mexicana-types in Coptophyllum and Anemirhiza, and the A. dregeana-type in Anemirhiza and Anemia. Spore polymorphism is indicated in several species of subgen. Anemia, and smooth immature spores are recorded from all three subgenera.