FUNK, V. A.* and HYIGYUNG KIM. U.S. National Herbarium, National Museum of Natural History, Smithsonian Institution, Washington D.C. 20560-0166, USA. - An evaluation of the proposed sister group relationships of the tribe Liabeae (Compositae).
Historically the members of the Liabeae (Compositae) were placed in
the tribes Vernonieae, Heliantheae, Helenieae, Senecioneae and/or
Mutisieae. In the 1970's Robinson brought the genera together into one
tribe and the most recent cladogram based on morphology weakly grouped
the Liabeae with the Vernonieae when compared with the Lactuceae.
Early molecular work in the family showed the Arctoteae, Liabeae,
Lactuceae, and Vernonieae in a variety of placements and resulted in
an unresolved polytomy or grade located between the tribe Mutisieae
and the subfamily Asterioideae. Recent Mutisieae and Liabeae DNA
sequence data have been combined with previously published sequence
data to address the placement of the Liabeae; the outgroups were a
clade of Asian and African Mutisieae, the core Mutisieae, and the
Cardueae. The results show that the four tribes form a monophyletic
group whose sister group is the Asterioideae. Within this four taxon
clade the Vernonieae, Liabeae, and Arctoteae form an unresolved
monophyletic group with the Lactuceae as its sister group. The
distribution of the tribes in the four taxon clade is interesting
because the members of the Liabeae are primarily Andean, those of the
Vernonieae are mostly found in Brazil and tropical Africa, and the
Arctoteae taxa are confined to southern Africa, so that the three form
a southern hemisphere clade, while the distribution of the Lactuceae
is Laurasian.
Key words: biogeography, Compositae, Liabeae