Seed morphology of Iberian species of the genus Aconitum L.

Abstract

A biometric-morphological study of the seeds of the taxons of the genus Aconitum L. occurring in the Iberian peninsula is given. The following features are treated: 1) arrange- ment of the seeds on the follicle, 2) definition of the parameters (general shape and ornamentation of the episperm), 3) biometry, and 4) description of the seeds of the Iberian taxa. Microcharacteristics related to the seed coat, shape and ornamentation of the insertion base (hilum and surrounding cells) have been found most useful in differentiating the taxa; furthermore, they may provide more phylogenetic information than other features. The results given agree generally with those reported by other authors (SEITZ, 1969 ; CAPPELETTI & POLDINI, 1984 ) but some important discrepancies have been noted with reference to seminal morphology, particularly episperm ornamentation in the species A. anthora, A. napellus s.l., A. burnatii and A. vulparia subsp. ranunculifolium. Seminal polymorphism is frequently observed in different geographically isolated colonies of the same species or subspecies, both in the Iberian Peninsula and in Central and Southern Europe. We conclude that polymorphism is further evidence of the phenotypical flexibility of this genus, probably owing to genetic drift in the populations. This flexibility is particu? la r important in colonizing species of wide ecological valence {A. napellus, s.l.; A. vulparia s.l.).