Pollen morphology in Cytisus (Papilionoideae, Leguminosae) from Morocco and the Iberian Peninsula

Although it is generally accepted that the tribe Genisteae has rather homog eneous pollen, we have found considerable variation in pollen size and morp hology in Cytisus and related genera (Argyrocytisus and Chamaecytisus), whi ch match taxonomic groups defined on morphological grounds. The results of Principal Component Analysis of pollen characteristics show the following: Cytisus Sect. Alburnoides is well-delimited, with the smallest pollen grain s and the simplest pattern in the lectum, fossulate-perforate to perforate; No separation of C. villosus (Sect. Cytisus) from Sect. Alburnoides is obs erved; Cytisus Sect. Spartopsis, with the largest pollen grains and reticul ate to reticulate-fossulate ornamentation, forms an isolated group; C. font anesii (Sect. Heterocytisus) stands apart from other Cytisus species by its homogeneous ornamentation and the perforate instead of psilate-punctate ma rgo. Thus, the pollen data supports its transfer to the separated genus Chr onanthos; Pollen ornamentation and morphology also support the separation o f Argyrocytisus battandieri and Chamaecytisus mollis from Cytisus.