| Abstract Detail
Systematics Section/ASPT Léveillé-Bourret, Étienne [1], Donadío, Sabina [2], Gilmour, Claire N. [1], Starr, Julian R. [1]. Rhodoscirpus (Scirpeae, Cyperaceae), a new South American sedge genus supported by molecular, morphological, anatomical and embryological data. In its broadest sense, Scirpus L. consists of a heterogeneous assemblage of up to 250 species, but modern circumscriptions suggest that only 40–50 species are part of the genus. Despite a narrower definition of the genus, atypical species continue to be segregated from Scirpus with a common pattern being the removal of Southern Hemisphere taxa to other genera and tribes. In South America, the morphology of remaining Scirpus species also suggests that they are not closely related to Scirpus s.s., but most of these taxa are only known from their types, making a detailed analysis of their generic affinities difficult. One notable exception is Scirpus asper J.Presl & C.Presl, a species that is relatively common in the mountains and adjacent lowlands of Peru south to Argentina. Although this species possesses features used in the circumscription of Scirpus, such as cauline leaves, flat leaf blades and anthelate inflorescences, it is known to differ from Scirpus s.s. by its Schoenus-type embryo, and most of its presumed allies are now placed in different genera (e.g. Scirpus analecti Beetle ≡ Cypringlea analecta (Beetle) M.T.Strong, Scirpus giganteus Kunth ≡ Androtrichum giganteum (Kunth) H.Pfeiff.). In this study, we use DNA sequence data from the plastid (matK, ndhF) and nuclear (ETS-1f) genomes to demonstrate that Scirpus asper is not closely related to Scirpus s.s., but sister to Phylloscirpus C.B.Clarke within the predominantly South American Zameioscirpus-clade (Amphiscirpus Oteng-Yeb., Phylloscirpus & Zameioscirpus Dhooge & Goetgh.). When combined with morphological, anatomical and embryological data, results indicate that S. asper is best treated as the sole species of a new monotypic genus, Rhodoscirpus Léveillé-Bourret, Donadío & J.R.Starr. The implications of these results on the taxonomy of tribe Scirpeae are discussed.
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Plant Systematics & Evolution lab at the University of Ottawa
1 - University of Ottawa, Biology, 30 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
2 - Instituto de Botánica Darwinion, Labardén 200, C.C. 22, San Isidro, B1642HYD, Argentina
Keywords:
Amphiscirpus
Andes
Phylloscirpus
Phylogeny
Scirpus asper
Scirpus trachycaulos
taxonomy
Zameioscirpus.
Presentation Type: Oral Paper:Papers for Sections
Session: 31
Location: Salon 4/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 9:00 AM
Number: 31005
Abstract ID:138
Candidate for Awards:George R. Cooley Award,Cinq Mars Award |
