XVI International Botanical Congess

Scolecopteris (Marattiales) is a late Carboniferous fertile fern genus containing 29 species. Due to a broad diagnosis, the genus is morphologically heterogeneous and may be unnatural. In a phenetic study, Millay (1979) partitioned Scolecopteris into four groups based on characters of the pinnule, synangia, and spores. Cladistic studies by Millay (1987) and Lesnikowska (1989) support the distinctness of these groups. Based on these studies, two of Millay's groups, Minor and Oliveri, may share a common ancestor, also, there is considerable variability within the Oliveri group. However, the Alta and Latifolia groups are each monophyletic, show little morphological variability, and should probably be circumscribed as generic segregates.