Contributions towards a revised infrageneric classification of Crepis (Cichorieae, Compositae)

• Autores: Neela Enke
• Localización: Willdenowia: Annals of the Botanic Garden and Botanical Museum Berlin-Dahlem, ISSN 0511-9618, ISSN-e 1868-6397, Vol. 39, Nº. 2, 2009, págs. 229-245
• Idioma: inglés
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• Resumen

  • A recent molecular analysis of Crepis by Enke & Gemeinholzer based on ITS and matK sequences proved the genus to be polyphyletic and split into three statistically well supported clades. The first clade comprises the majority of the sampled species as Crepis s.str., the second clade species of five Crepis sections (Intybellia, Lagoseris, Phaecasium, Microcephalum and Pterotheca) as well as the genera Lapsana and Rhagadiolus, the third clade C. sect. Ixeridopsis as part of the Youngia group. The present paper summarises and discusses the available molecular, morphological (additional micromorphological data of pollen, achenes and pappus presented in the present paper) and karyological findings, makes suggestions towards delimitation and infrageneric classification of Crepis and specifies problems to be solved by future studies. It is concluded that (1) the recent resurrection of Askellia as a separate genus is well advised, (2) the genera Lapsana and Rhagadiolus should, for the time being, be maintained in their current generic circumscription and (3) Crepis, consequently, be treated as a paraphyletic taxon. A revised infrageneric classification of Crepis, maintaining 21 of Babcock's 27 sections, some in a revised circumscription, is provided; in addition, C. sect. Calliopea is re-established and C. sect. Neglectoides is described as new to science. For several species or species groups the findings are ambiguous or contradicting and their placement questionable. Approximately 55 % of the species were not included in a molecular analysis yet and their sectional placement based on morphological data only is thus tentative.