A preliminary phylogeny of Senecio series Culcitium

LUCIANA SALOMON; SILVANA M. SEDE; SUSANA E. FREIRE

Buenos Aires

Congreso; 35th Annual Meeting of the William Henning Society; 2016

William Henning Society

Senecio series Culcitium, based on the genus Culcitium, includes 35 andean species distributed in South America from Venezuela to northwestern Argentina, which are characterized by its capitula usually discoid and nodding with developed calycular bracts, and style arms ranging from apically papillate to papillate with a tuft of longer hairs. The phylogenetic relationships of Senecio ser. Culcitium were examined using DNA sequences from the nuclear ribosomal ITS region and plastid trnK, including 18 of the 35 species in the group, and also seven species recently excluded from it, i.e. Senecio aspleniifolius, S. candidans, S. diemii, S. gilliesii, S. jarae, S. magellanicus, and S. martinensis, seven new species were analyzed together with previously published sequences in order to generate a topology. Our results support Senecio ser. Culcitium as paraphyletic, the monophyly of the series depends upon the inclusion of Senecio algens. Based on our topology we confirm the exclusion of S. aspleniifolius, S. candidans, S. diemii, S. gilliesii, S. jarae, S. magellanicus, and S. martinensis from the series and the placement in two different series, Hualtatini and Repentes, and in one informal clade, the ?diemii group?. The ?diemii group?, present in the southern Andes of Argentina and Chile, includes S. diemii, S. magellanicus, and S. martinensis. Senecio gilliesii and S. candidans are considered within ser. Hualtatini, mainly distributed in the southern Andes and in southernBrazil. Finally, Senecio jarae and S. aspleniifolius are classified within Senecio ser. Repentes, present in the Central Andes of Argentina and Chile.