Pollen of Zingiberales from the Rio de la Plata wetlands and subtropical rainforests of northeastern Argentina

Abstract

A study of the morphology of the pollen of native, naturalized, and cultivated representatives of Zingiberales growing in the Río de La Plata wetlands, and Northeastern subtropical rainforests of the Argentina, was performed with light and electron microscopy. The analyzed species were C. glauca and C. indica (Cannaceae), Heliconia psittacorum, H. brasiliensis and H. rostrata (Heliconiaceae), Thalia geniculata and Maranta leuconeura (Marantaceae), Musa acuminata × balbisiana y M. × paradisiaca (Musaceae), Strelitzia nicolai and S. reginae (Strelitziaceae), Alpinia zerumbet, Hedychium coronarium and H. gardnerianum (Zingiberaceae). Spheroid, oblate, apolar and heteropolar, inaperturate grains were found, with thin exines, and thicker, two-layered intines. The ornamentation types were echinate, typical and micro-echinate, found in Cannaceae, Heliconiaceae, and some Zingiberaceae, muriforme types (rugate, rugulate, and areolate), and smooth or psilate exine surface ornamentations, present in Musaceae, Strelitziaceae and Zingiberaceae. Thalia geniculata smooth grains, Musaceae rugate grains, and Strelitziaceae areolate grains are described here by the first time. Other traits were analyzed, such as the presence of elastine threads and pollenkitt. All these characters contribute to an update of the knowledge of these selected taxa, scarcely known from a palynological point of view.