Pollen morphology of species of Graphistylis B. Nord. (Asteraceae) of Brazil

Mariana Albuquerque de Souza,Claudia Barbieri Ferreira Mendonça,Roberto Lourenço Esteves,Vania Gonçalves-Esteves

doi:10.1590/0102-33062015abb0300

Mariana Albuquerque de Souza, Claudia Barbieri Ferreira Mendonça + Show 2 more

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https://doi.org/10.1590/0102-33062015abb0300

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Abstract

This paper presents the results of a palynological study of the species ofGraphistylis that were segregated fromSenecio (s.l.) (Seneciosect. Dichroa) and that are all endemic of Brazil. These species are found in mountainous regions of the states of Espirito Santo, Minas Gerais, Parana, Rio de Janeiro, Sao Paulo and Santa Catarina. The pollen grains of eight species were acetolyzed and analyzed and photographed using light microscopy. Unacetolyzed pollen grains were analyzed and photomicrographed using scanning electron microscopy. The current study undertook a palynologically analysis of Graphistylis in order to obtain information useful for making a better ranking of these genus. The results show medium-sized pollen grains that were oblate spheroidal or prolate spheroidal and subtriangular amb and tricolporate. The pollen grains possessed lalongate endoapertures with a median constriction and the presence of costa in only two species. The exine is echinate with a varying number of spines in the apocolpium region around the central spine in polar view. The spines are short with basal perforations at varying distances. Although the morphology of the pollen of species ofGraphistylis is very similar, multivariate analysis highlights the importance of quantitative traits in distinguishing species.

Highlights

This paper presents the results of a palynological study of the species of Graphistylis that were segregated from Senecio (s.l.)
The genus Graphistylis is endemic to Brazil where it is found in the mountainous regions of the states of Espírito Santo, Minas Gerais, Rio de Janeiro, São Paulo, Paraná and Santa Catarina (Nordenstam 1978; Jeffrey 1992)
The smallest confidence intervals for polar and equatorial diameters in equatorial view were for G. toledoi (PD=36.0-37.2 m; Equatorial diameter (ED)= 36.7-37.9 m), and the largest for G. cuneifolia (PD= 48.9-49.7 m; ED= 49.1-50.3 m)

Summary

Introduction

The genus Graphistylis is endemic to Brazil where it is found in the mountainous regions of the states of Espírito Santo, Minas Gerais, Rio de Janeiro, São Paulo, Paraná and Santa Catarina (Nordenstam 1978; Jeffrey 1992). It is in the tribe Senecioneae (Cassini 1818), which is considered the largest tribe of Asteraceae with approximately 3500 species distributed among 150 genera (Nordenstam 2007). Graphitylis was created by Nordenstam (1978) for all six of the species of Senecio sect. Senecio serranus, endemic to Paraná. Hind (1993) placed Cacalia dichroa in Graphistylis (G. dichroa) and, a year later, Nordenstam (1994) proposed the combination Graphistylis serrana for Senecio serranus. Teles & Nordenstam (2008)

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