Spore Morphology of Anemia Subgenus Coptophyllum

Abstract

Anemia Swartz is a genus of leptosporangiate ferns consisting of approximately 90 species. The genus inhabits tropical and semitropical latitudes in Africa, India, and the Americas, with two species reaching the United States. Anemia generally is divided into three subgenera: Coptophyllum, Anemiorrhiza, and Anemia. The present study deals with a scanning electron microscopic examination of spores of six species of subg. Coptophyllum, four of which are endemic to the Planalto region of south-central Brazil. Subgenus Coptophyllum has been monographed by Mickel (1962), who noted spore morphology as viewed with a light microscope. Previous studies of Anemia spores also include the work of Erdtman (1957). The spores of Anemia are unique among ferns in their tetrahedral shape and surface pattern of conspicuous ridges separated by striae. Protuberances or ridge extensions occur where the ridges join the trilete scar. The present study was undertaken in an attempt to discover morphological details not visible in light microscopy that might be of taxonomic value. While I was the field assistant to Dr. William R. Anderson on the 1973 New York Botanical Garden Expedition to the Planalto region of south-central Brazil, I collected spore samples of various Anemia species. All were air-dried. Spore samples of six species, 18 specimens altogether, belonging to subg. Coptophyllum were mounted on aluminum studs with double-adhesive tape and coated with a thin (200-400A) layer of gold-palladium. The samples were then examined at 15 kv and photographed using the JEOL JSM-U3 Scanning Electron Microscope (SEM) of the Electron Microscopy Center, Texas A & M University. To best facilitate comparisons, proximal, distal, and ornamentation micrographs were included for all species examined. Measures and magnifications are based upon those indicated by the instrument. Although absolute accuracy in magnification is rare in the SEM, relative measures between the spores can be assumed to be correct. In the following listing, collections cited with an asterisk are illustrated in this paper. The specimens examined, all of which were from Brazil, are: A. elegans (Gardn.) Presl.-Goias: Alto do Paraiso, Anderson, Hill, et al. 6670; Serra dos Cristais, Anderson, Hill, et al. 8186; Serra Dourada, Anderson, Hill, et al. 9982; Serra dos Pireneus, Anderson, Hill, et al. 10295.* Matto Grosso: Barra dos Gargas, Anderson, Hill, et al. 9823. A ferruginea H.B.K.--Goias: Alto do Paraiso, Anderson, Hill, et al. 6794; Serra dos Pireneus, Anderson, Hill, et al. 10344. Minas Gerais: Serro do Espinhago, Anderson, Hill, et al. 8415, 8767.* Matto Grosso: Barra dos Gargas, Anderson, Hill, et al. 9904. A. glareosa Gardn.-Goias: Alto do Paraiso, Anderson, Hill, et al. 6655; Serra Dourada, Anderson, Hill, et al. 9983.*