Taxonomic changes in C3 Cyperus (Cyperaceae) supported by molecular data, morphology, embryography, ontogeny and anatomy

Abstract

Background and aims -Recent molecular studies validate a broad definition of Cyperus (Cyperaceae) uniting genera previously scattered in Cyperoideae. First indication of their affinity with Cyperus was obtained through embryography. Cyperus consists of a paraphyletic C 3 Cyperus and monophyletic C 4 Cyperus. In this study, we aim to check and clarify the putative positions of the segregate genera in C 3 Cyperus. Additional information is given and remarks are made on the position of some as yet unplaced species or sections in the C 3 Cyperus phylogeny. Methods -Embryos of Cyperus constanzae and C. gardneri were cleared and drawn. Inflorescences of selected C 3 Cyperus species were investigated using scanning electron and light microscopy. Histochemical tests were performed to assess the presence of suberin in the 'corky' tissue of the nutlets of Cyperus pectinatus. Key results -Embryography not only supports tribal classification in Cyperoideae, it is also phylogenetically informative in C 3 Cyperus. Morphology and ontogeny support molecular phylogenetic results suggesting the inclusion of the segregate genera in C 3 Cyperus as new sections or in established sections, and confirm the need to broaden the circumscription of some of these sections. Conclusion -Although less diverse than C 4 Cyperus, C 3 Cyperus includes clades which evolved an exceptional morphological diversity compared to its limited species numbers. The segregate genera Courtoisina (deciduous spikelets), Kyllingiella (spirally-arranged glumes) and Oxycaryum (spirallyarranged glumes and dorsiventrally flattened dimerous gynoecia), and the taxon Anosporum (recognised at sectional, subgeneric or generic level) are here included in C 3 Cyperus (= Cyperus subg. Anosporum) as sections or included in an existing section (Kyllingiella is included in Cyperus sect. Leucocephali). A formal taxonomic revision is presented with relevant new names and combinations, synonyms, diagnoses and identification keys.

Affinities in C3Cyperus lineages (Cyperaceae) revealed using molecular phylogenetic data and carbon isotope analysis

“…The classification used is that of Goetghebeur (1998). A paper documenting the necessary nomenclatural/taxonomical changes based on the results presented in this paper and further supported by morphological, embryological, ontogenetic and anatomical data will be published elsewhere (Larridon et al ., in press). The final objective of the research on Cyperus carried out by the authors is to recircumscribe the genus so that it is monophyletic and to create a new infrageneric classification of the genus supported by both molecular and morphological data.…”

“…Courtoisina is characterized by its yellowish green colour, flattened spikelets which disarticulate as a unit when mature, leaving the spikelet bract and prophyll behind, often conspicuously winged glumes, and linear–lanceolate to linear–oblong nutlets. A further paper will focus in more detail on the C 3 Cyperus segregate genera and the necessary nomenclatural/taxonomic changes to include these taxa into a monophyletic genus Cyperus (Larridon et al ., in press).…”

“…However, the recent discoveries of new species, and its intricate relationship with Kyllingiella , rather indicate a lack of knowledge of this group. A formal taxonomic revision with the inclusion of Kyllingiella in Cyperus will be published elsewhere (Larridon et al ., in press).…”

Flora das cangas da Serra dos Carajás, Pará, Brasil: Cyperaceae

“…Filogenias recentes (Larridon et al 2011a;2011b;2011c;2013) indicam Cyperus monofilético com a inclusão Kyllinga Rottb., Lipocarpha R. Br., Pycreus Beauv.…”

Phylogenetic position of Cyperus clandestinus (Cypereae, Cyperaceae) clarified by morphological and molecular evidence

“…Within the Cyperus clade, our results are similar to previous studies (Muasya et al 2009a, Larridon et al 2011a), where Androtrichum trigynum is sister to the rest of the taxa and there is a grade of C 3 clades together with a strongly supported C 4 clade. Androtrichum giganteum is not sister to A. trigynum , but the former is strongly supported as part of clade 3 of Larridon et al (2011a, 2011b), together with taxa in Cyperus subgenus Anosporum (sect. Fusca, Courtoisina and Oxycaryum ).…”