Variation in the tracheoids of seeds from the subtribe pithecocteniinae (Bignonieae: Bignoniaceae) and their contribution to the systematics of the group

Abstract

The diversity of ornamentations present in the tracheoids of seed surface from species of the subtribe Pithecocteniinae (genera Amphilophium, Distictella, Distictis, Glaziovia, Haplolophium, and Pithecoctenium) in the Bignoniaceae is described. Three distinct ornamentation types were observed on the tracheoid surfaces: (1) Tracheoids without ornaments (in the genera Amphilophium, Glaziovia and Haplolophium), (2) ornaments in true helices (in the genera Distictis and Distictella), and (3) ornaments in pseudo-helices (in the genus Pithecoctenium). The taxonomic value of these tracheoid ornaments to establish possible relationships within the subtribe Pithecocteniinae is discussed.