Format: ORAL

Constantin I. Fomichev1,2, Terry D. Macfarlane3, Barbara G. Briggs4, Dmitry D. Sokoloff1

1 Lomonosov Moscow State University, Moscow, Russia 2 Shenzhen MSU–BIT University, Shenzhen, China 3 Western Australian Herbarium, Perth, Australia 4 National Herbarium of New South Wales, Sydney, Australia

Despite great taxonomic diversity and a significant role in the vegetation of Australia and South Africa, Restionaceae remain quite difficult in genus and species identification for non-specialists. The problem is at least partly caused by the insufficient amount of morphological data on Restionaceae based on homology instead of a descriptive approach. Well-defined morphological characters can indicate the accurate similarities and differences of taxa and are especially significant for systematics. Restionaceae are well-known for their commonly short and inconsipuous leaf lamina. To date, identification of Restionaceae commonly ignores some leaf characters, e.g., fusion of sheath edges, details of leaf sheath to lamina transition, and lamina morphology. Our analysis of the leaf charters of Australian Restionanceae indicates the taxonomical significance of foliar morphology. For example, we used the occurrence of a long leaf ligule (up to 1.5 cm) as a new character to distinguish species in Anarthria (a genus with unusually well-developed leaf lamina). We revealed, also using molecular data and micromorphology, that the commonly accepted species, Anarthria gracilis, represents a species complex comprising three distinct species. We present and analyse a new data set on key characters of leaf morphology, including fine details of sheath to lamina transition, for all genera of Australian Resionaceae. A case study of Leptocarpus denmarkicus provides an example of new knowledge on inflorescence morphology. We show that the female inflorescence unit in L. denmarkicus is a double rather than a simple spike. Spirally arranged glumes represent pherophylls bearing reduced lateral spikelets. Each true spikelet has two bracts, of which one is fertile and subtends a flower. Analogous situations may occur in other Restionaceae. Our aim is to produce a homology-based compendium of morphological character evolution in Restionaceae and to assess the adaptive value of taxonomic characters.