Taxonomic revision of the genus Calendula L. (Asteraceae – Calenduleae) in the Canary Islands

• Autor(a) principal: Simão, Inês da Fonseca
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/35794
• topic: Calendula; Asteraceae; Canary Islands; Taxonomy; DNA nuclear content; Cromossomatic number

A taxonomic revision of the Calendula L. genus (Asteraceae – Calenduleae) for the Canary Islands is presented. Following the most recent and complete revision work done on the genus, the Canary Islands remained as one of the only territories of distribution of Calendula that currently lacks a comprehensive taxonomical study of its species, the relations between taxa, their ecology, and areas of distribution, among other factors. With this goal, an extensive morphometric analysis was conducted on several herbaria specimens and specimens collected in expedition, as well as chromosome counts and genome size estimates. Genetic information such as chromosome numbers and nuclear DNA content can be a powerfully ally, indicating taxonomic heterogeneity and influencing taxa delimitation, especially in genera as complex as Calendula, which possess a large morphological variability, tendency for hybridization and polyploidization. Four species of Calendula were recognized for the islands- C. arvensis, C. officinalis, C. ricardii, and C. sventenii-, two of them corresponding to new taxa. Descriptions and conservation assessments for each taxon, as well as an identification key are presented.