Nuptial nectary structure of Bignoniaceae from Argentina

Abstract

"Rivera, G. L. 2000. Nuptial nectary structure of Bignoniaceae from Argentina.Darwiniana 38(3-4): 227-239.Nuptial nectary characteristics were investigated in 37 taxa of Bignoniaceae. A nuptial nectaryassociated to the floral axis was found in all species. Two main types can be distinguished according totheir degree of development and functionality: 1) vestigial and non-secretory and 2) well-developed andsecretory. The former is characteristic of Clytostoma spp., while the latter is found in the remainingspecies. Two subvarieties of the secretory type of nectary can be discerned according to their positionand shape: 1) annular, found in Adenocalymma, Amphilophium, Anemopaegma, Arrabidaea,Dolichandra, Eccremocarpus, Macfadyena, Melloa, Pithecoctenium, Tabebuia, and Tecoma, and 2)cylindrical, found in Argylia, Cuspidaria, Jacaranda, Mansoa, Parabignonia, Pyrostegia, andTynnanthus. Anatomically, two tissues are distinguished: 1) a single-layered epidermis covered by acuticle and a variable number of stomata, and 2) a secretory tissue composed of compactly arrangedparenchyma cells. Both nectary size and nectary/ovary ratio were usually larger in lianas (Bignonieae)than in trees (Tecomeae). Nectary type proved to be consistent among species of same genus but notamong genera of same tribe. Nectary features such as vascularization, presence of trichomes and nectarytype were constant within the analyzed species and therefore have a reliable taxonomic value"