A preliminary phylogeny of Liabum (Asteraceae, Liabeae) inferred from morphology

GUTIÉRREZ, D. G.

Barcelona

Congreso; The International Compositae Alliance; 2006

Institut Botánic de Barcelona

Liabum (Asteraceae, Liabeae) is a Neotropical genus of ca. 30 species distributed from southeeastern Mexico to northwestern Argentina through the Andes. Also, it occurs in Cuba, Hispaniola, and Jamaica. A preliminary phylogenetic analysis based on a detailed morphological study is provided. Species of Cacosmia, Ferreyranthus, and Oligactis were used as the outgroups. Twelve most parsimonious cladograms were obtained based on the data set using Pee-Wee 3.0 (Parsimony and Implied Weights). As a result, Liabum can be considered a monophyletic group (excluding L. diehlii) with acrodromous leaves, more than 20 rays per capitulum, disc florets with gradually differenciate corolla, long style branches, and style with pubescence portion below the bifurcation point equal or shorter than the style branches. According to one of the 12 hypothesis, L. ferreyri, and L. melastomoides were the sister species of the rest of genus Liabum. Within the main clade, five unresolved phylogenetic subgroups are indentified: group (1): L. barclayae, L. igniarium, and L. solidagineum; group (2): L. saloyense and L. kingii; group (3): L. floribundum, L. nigropilosum, and L. stipulatum; group (4): L. saundersii and L. wurdackii; group (5): L. acuminatum, L amplexicaule, L. asclepiadeum, L. eriocaulon, L. grandiflorum, L. macbridei, L. steinbachii, L. vargasii, and the five West Indian species. The cladograms differed mainly in the resolution of the polytomy including L. diehlii. In one of the cladograms L. diehlii was the sister group of the rest of the species of Liabum; in the second alternative, L. diehlii was nested in Oligactis.