A revised classification of subtribe Helianthinae (Asteraceae: Heliantheae) II. Derived lineages

Abstract

Sequence data for internal transcribed spacer (ITS) and partial external transcribed spacer (ETS) regions were combined in a phylogenetic analysis with previously obtained plastid DNA restriction site data to provide a comprehensive molecular phylogenetic hypothesis for derived members of subtribe Helianthinae. Analyses of the two molecular datasets provided conflicting evidence on relationships among some groups, supporting the hypothesis that hybridization has played a significant role in the divergence of the subtribe. A revised generic-level classification is presented that divides the approximately 350 species of the subtribe among 21 genera. The paraphyletic Viguiera is narrowed to embrace only the type species, V. dentata. Four newly described genera, Dendroviguiera, Gonzalezia, Heiseria and Sidneya, are composed of species formerly included in Viguiera. Aldama is expanded to include 118 species extending from southwestern North America and Mexico to South America. This requires 116 new combinations, including 58 that were recently transferred into Rhysolepis, which is a synonym of Aldama, based on molecular phylogenetic results. One species of Viguiera is transferred to Tithonia, and two combinations in Hymenostephium are validated.

Fitogeografia de Aldama (Asteraceae, Heliantheae) na América do Sul

“…Com a transferência, baseada em resultados de filogenia molecular (Schilling & Panero 2011), das espécies sulamericanas de Viguiera Kunth sensu Blake (1918) para esse gênero, o número de espécies foi elevado para cerca de 120 espécies (Schilling & Panero 2011;Magenta & Pirani 2014). Nesta circunscrição, Aldama é um gênero americano, encontrado no sudoeste da América do Norte e México, e na América do Sul (Schilling & Panero 2011), que ocorre predominantemente em regiões montanhosas e/ou abertas. Seus representantes são ervas geralmente perenes, com sistema subterrâneo espessado, sinflorescências com paracládios quase sempre alternos, cipselas simétricas ou levemente assimétricas, ligeiramente compressas, com pápus biaristado e escamas decíduas ou persistentes entre as aristas.…”

Seed germination of Brazilian Aldama species (Asteraceae)

“…The genus Aldama La Llave belongs to the Asteraceae family and includes South American species previously classified as Viguiera sensu lato (Schilling and Panero, 2011). Brazilian species from this genus occur mainly in the Cerrado regions in climates that have dry winters (Magenta et al, 2010), and these species are most often observed under such conditions that may be related to the type of thickened underground system, which supports the plants' water needs during dormancy (Zaidan and Carreira, 2008;Magenta et al, 2010) and is essential for regenerating the vegetative aerial portions (Oliveira et al, 2013;Bombo et al, 2014).…”

Can climate and soil conditions change the morpho-anatomy among individuals from different localities? A case study in Aldama grandiflora (Asteraceae)

“…Among its representatives is Aldama La Llave, a South American genus, which includes 35 Brazilian species, of which 17 are endemic (Magenta et al, 2010). The representatives of this genus are morphologically very similar, leading to problems in taxonomical delimitations among the species (Schilling and Panero, 2011).…”