A cladistic analysis of Nassauvia Comm ex Juss

Authors: FREIRE SUSANA E CRISCI JORGE V KATINAS LILIANA

Publish Date: 1993/08/01

Volume: 112, Issue: 4, Pages: 293-309

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Abstract

SUSANA E FREIRE JORGE V CRISCI LILIANA KATINAS A cladistic analysis of Nassauvia Comm ex Juss Asteraceae Mutisieae and related genera Botanical Journal of the Linnean Society Volume 112 Issue 4 August 1993 Pages 293–309 https//doiorg/101111/j109583391993tb00321xNassauvia and the most closely related genera Calopappus and Triptilion from the southern Andes and Patagonia of South America form a monophyletic group diagnosed by the following synapomorphies cypsela trichomes single twocelled cypsela testa with strengthened cells pollen grains spheroidal to spheroidaloblate colpi membrane with sexine processes pappus bristles two to six and pappus deciduous Furthermore Nassauvia Triptilion and Calopappus form a group with two other Andean genera Moscharia and Polyachyrus diagnosed by occurrence of pseudocephalia and a reduction in the number of flowers to five three or one A cladistic analysis of the group was undertaken using 35 characters from morphology anatomy and palynology The monophyletic terminal taxa were the 38 species of Nassauvia the genus Triptilion the monotypic genus Calopappus the genus Polyachyrus and the genus Moscharia Character polarity was based on outgroup comparison using Cephalopappus The analysis resulted in 223 equally parsimonious cladograms each with 70 steps and a consistency index of 057 A successive weighting procedure was applied resulting in 15 cladograms with a consistency index of 082 Results of the cladistic analysis support most of the current systematic classification of Nassauvia with three exceptions 1 Nassauvia excluding Calopappus is paraphyletic 2 section Masligophorus appears to be a polyphyletic group N pygmaea does not cluster with the remaining species of the section 3 section Panargyrum without N lagascae = section Caloptilium appears to be a paraphyletic group The capitula arranged in cymose conflorescences in Triptilion are regarded as a primitive condition which gave rise to all stages present in Nassauvia conflorescence spicate pseudocephalium capitula solitary The capitula arranged in pseudocephalia in Moscharia and Polyachyrus are regarded as a parallel development to the pseudocephalium found in Nassauvia Nassauvia subgenus Strongyloma appears as the most primitive taxon with its spicate conflorescence whereas section Masligophorus with its solitary capitulum is thoughtderived These results correspond well with cytological data where species of the subgenus Strongyloma have n = 11 and the species of section Masligophorus are tetraploids n = 22

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