Palynological study of species of Trixis P.Browne (Mutisieae, Asteraceae) ocurring in the State Rio de Janeiro, Brazil

Abstract

We analised the pollen morphology of Trixis antimenorrhea (Schrank) Kuntze subsp. antimenorrhoea, T. glaziovii Baker, T. lessingii DC., T. nobilis (Vell.) Katinas, T. praestans (Vell) Cabrera, and T. verbascifolia (Gardner) Blake subsp. verbascifolia. The samples were obtained from dried herbarium specimens deposited in herbaria of Rio de Janeiro State. Pollen grains were acetolysed, measured, described, analysed, and illustrated using light microscopy. Scanning electron micrographs were obtained using non-acetolysed material. The obtained results indicate that pollen grains vary from medium to large size, are prolate, tricolporate, have a spinulous surface, a notorious thick sexine in the polar area with increased length of the collumelae. The colpus generally presents a granulate membrane and a lalongate endoaperture. The pollen grain morphology enabled to separate the species, but we concluded that the taxa have some pollinic homogeneity.