Morfologia polínica da vegetação da restinga de Algodoal-PA. VII - família Asteraceae

Abstract

The islands of Algodoal and Maiandeua in Maracanã, Pará, Brazil are known for their lush mangrove and restinga vegetation with morphologically distinct vegetational communities. The term "restinga" denotes the type of sparse vegetation predominant on the coastal beaches of the coast of Pará. The restingas and the mangroves are areas lacking scientific studies, given their rapid degeneration. Many of the coastal ecosystems already present a very high degree of destruction, without any study having been done to recognize the populations that exist there. For this study, we investigated the pollen of seven species of the Asteraceae family i Acantbospermum australis and O. Kuntze, Ambrosia microcepbala DC., Bclipta alba Hassk., Emitia sonchifolia (L.) DC., Mikania congesta DC., Vernonia arenaria Mart. ex DC. and Wu (ffia baccata O.Kuntze). All samples of pollen grains from the above mentioned species were submitted to Erdtman's acetolysis method. Afterwards, the grains were measured and their morphological characteristics described. It was observed that the pollen grains of the investigated species are very similar, mainly regarding the number of openings and the ornamentation of the exine, except for Ambrosia microcephala that presents a spiculated surface and Vernonia arenaria, reticulate with spines. The pollen grains of the other species have a spiny surface, varying only in size, from small to medium. We again conclude that the Asteraceae family is stenopolinic, due to the high degree of homogeneity among the species studied, despite belonging to distinct genera.