Estudio palinológico de Colobanthus (Caryophyllaceae) en Argentina

Abstract

Pollen grains of the three species of the genus Colobanthus (Caryophyllaceae) in Argentina has been studied. Acetolyzed grains have been examined with light and scanning electron microscopy and the average measurements were: 29.20 µm in diameter, 29 pores, 1.00 µm in sexine thickness, 0.87 µm in nexine thickness in C. lycopodioides Griseb.; 33.57 µm, 28 pores, 1.66 µm, 0.94 µm in C. quitensis (Kunth) Bartl. and 32.07 µm, 28 pores, 1.41 µm, 0.74 µm in C. subulatus (D’Urv.) J. D. Hooker. In the three species the microspores separate forming monads. The pollen grains are spheroidal, tectate with perforate and microequinate tectum, with columellae. They are pantoporate, with slightly sunken pores, ca. 2 µm in diameter, circular, covered with an operculum with spinules. Even if the averages show differences among the investigated species, the variability of the measurements has a wide range, that makes difficult the separation of the species using pollen grains characteristics.