Pollen Morphology of native and cultivated species of Handroanthus (Bignoniaceae) present in Argentina

Abstract

The aim of this work was to expand the palynological knowledge of the species of Handroanthus (Bignoniaceae) presents in Argentina and incorporate this material to the Atlas Polínico del NOA which is published on line (www.atlaspolinicodelnoa.com.ar). To accomplish this goal, the pollen morphology of H. albus (Cham.) Mattos, H. chrysotrichus (Mart. ex DC.) Mattos, H. heptaphyllus (Vell.) Mattos, H. impetiginosus (Mart.ex DC.) Mattos, H. lapacho (K. Schum.) Mattos, H. ochraceus (Cham.) Mattos and the exotic H. pulcherrimus (Sandwith) S. Grose was analyzed. The material was processed according to conventional techniques for natural pollen and acetolysis. Photos at the level of optical microscopy (OM) and scanning electron microscopy (SEM) were taken. The grains are medium size, from 25 - 31,6 µm in the natural pollen and 27,45 - 48 µm in those acetolyzed, suboblate to subprolate. Three-colporated (colporoidated) in H. albus, H. chrysotrichus, H. heptaphyllus, H. impetiginosus, H. lapacho and H. pulcherrimus and 3-colporated (colporoidated), 3-hemisyncolporated and loxocolporated in H. ochraceus. The exine is 1.5 to 2 µm in thickness with a reticulated surface heterobrochate.