SEED MORPHOLOGY OF TWO DISTINCT EUROPEAN SPECIES OF ERICA L. (ERICACEAE)

Abstract

Erica spiculifolia is a distinct species within the genus Erica, considered by some authors as part of a monospecific genus: Bruckenthalia. The second species studied, E. umbellata, is the only European species of section Pyronium. Seed morphology of the two species was studied by means of SEM techniques. Seeds from different populations were used. Characters concerning size and shape of seeds, primary and secondary ornamentation were observed and measured. The seeds of E. spiculifolia are close to those of other species within the genus, supporting the inclusion in Erica. E. umbellata seeds have some exclusive characters within the European species of the genus: a verrucate secondary ornamentation and surface cells with “omega type” cell boundaries. The systematics of genus Erica is still unresolved, and the taxonomic position of these species has to be clarified. As found in previous studies, seed characters provide useful taxonomic characters that should be used in the interpretation of the taxonomic position of these species within Erica.