Bryological and Lichenological Section/ABLS
Zhang, Li , Stotler, Raymond E. , Crandall-Stotler, Barbara J. .
A Re-evaluation of Noteroclada Taylor ex Hook. & Wilson (Pelliaceae H. Klinggr., Marchantiophyta).
Noteroclada is a portmanteau genus that has had an unnatural assemblage of 10 taxa of large, lobate to leafy, anacrogynous liverworts assigned to it during a roughly 50 year period of the 19th century. To date, we have typified nine of those names and have found that one species belongs in the genus Treubia, three others represent species of the genus Fossombronia and one variety belongs to the genus Austrofossombronia. Preliminary studies suggest that four of the five remaining species are conspecific and the other is probably a species of Treubia. Although placed in the Pelliaceae in most modern classification schemes, Noteroclada often resolves with the Fossombroniaceae in molecular analyses. To clarify the systematic affinities of Noteroclada, a comparative study of sporophyte and sporeling development of N. confluens and Pellia epiphylla has been conducted. In both taxa spore germination is precocious and endosporic, but patterns of early division and juvenile plant morphologies are very different in the two. The following features of sporophyte anatomy are common to both taxa: 1) conical foot with a well developed involucellum; 2) generalized seta that remains photosynthetic until late stages of elongation; and 3) four-valved, bistratose capsule wall, with a basal tuft of elaters forming an elaterophore. However, the gametophytic structures that develop in association with the sporophyte are distinct, with a Fossombronia-like caulocalyx occurring in Noteroclada as compared to a pseudoperianth in Pellia. These findings support the interpretation of a phylogenetic link between the Fossombroniaceae and the Pelliaceae.
1 - Southern Illinois University, Department of Plant Biology, 1125 Lincoln Drive, Carbondale, Illinois, 62901-6509, USA
Presentation Type: Paper
Location: Ballroom 3 (Cliff Lodge)
Date: Monday, August 2nd, 2004
Time: 4:00 PM