Abstract

MAGENTA, Mara Angelina Galvão; NUNES, Alessandra De Deus; MENDONCA, Cláudia Barbieri Ferreira  and  GONCALVES-ESTEVES, Vânia. Palynotaxonomy of Brazilian Viguiera (Asteraceae) Species. Bol. Soc. Argent. Bot. [online]. 2010, vol.45, n.3-4, pp.285-299. ISSN 1851-2372.

With the aim of improving inter-specific delimitation of the genus Viguiera Kunth in Brazil, a palynological analysis was undertaken with 27 taxa, representing around 77% of all occurring species. Samples were obtained from herbarium specimens and the pollen grains were analyzed through light and scanning electron microscopy. Characteristics, including the shape of the pollen grains, polar and equatorial diameter, aperture measurements, surface ornamentation and exine thickness, were registered and compared. The pollen grains were medium-sized (25 - 50 mm), isopolar and oblate spheroidal (prolate spheroidal in V. aspilioides Baker). The observed values corroborated the synonymity of some species and also highlighted certain micro-morphological differences, such as polar diameter and the dimensions of the colpus and endoaperture, thus confirming the groups of species delimitation obtained by morphologic and phylogenetic analyses.

Keywords : Asteraceae; Brazil; Compositae; Pollen; Taxonomy; Viguiera.

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