Pollen Morphology of natives Nyctaginaceae of Argentina

Abstract

The pollen morphology of Argentinian genera and species of Nyctaginaceae was analized in order to provide detailed information and contribute for their identification in actual and fossil pollen dispersed. The Nyctaginaceae family in Argentina, is composed of 8 genera with 19 species included in the following tribes: Boungainvilleeae: Bougainvillea (B. campanulata, B. infesta, B. praecox, B. spinosa, B. stipitata). Colignonieae: Colignonia (C. glomerata). Nyctagineae: Allionia (A. choisyi, A. incarnata), Boerhavia (B. cordobensis, B. diffusa, B. pulchella, B. spicata), Mirabilis (M. bracteosa, M. jalapa, M. ovata). Leucastereae: Reichenbachia (R. paraguayensis). Pisonieae: Pisonia (P. aculeata, P. zapallo), Pisoniella (P. glabrata). The pollen material was processed according to the Erdtman techniques, described and illustrated with light microscope and scanning electron microscope. The pollen grains are apolar or isopolar, radiosimetric; small to medium size, subcircular, subtriangular or cuadrangular in polar view, spheroidal, prolato-spheroidal, oblate-spheroidal or suboblate form. Tricolpate, tetracolpate, pantoporate or pantocolpoidate. Tectate perforate exine or semitectate reticulate. Variability found between genus, allows to differentiate them with the exception of Allionia and Mirabilis. In the genus represented with more than one species, Allionia, Boerhavia, Bougainvillea, and Mirabilis, it is not possible to differentiate the species from one another by the homogeneity and superposition of their characters, but it is possible in Pisonia. Keys for the identification are presented.