Seed morphology of the European species of Erica L. sect. Arsace Salisb. ex Benth. (Ericaceae)

Abstract

The seed morphology of Erica arborea and E. lusitanica, the two European species of section Arsace, was studied. The results reflect very significant differences between the two species, mainly in size and shape of the seeds, testa sculpture and surface cells boundaries. The seeds of E. arborea are larger, with a striated pattern and anastomosed cells, while E. lusitanica has seeds below 0.4 mm, rounder and with a reticulate surface pattern and channelled cell boundaries. The seeds of E. arborea are grouped in two main seed types that correspond to the Macaronesian and the Iberian peninsular populations. Some African, Central and Eastern Mediterranean populations have intermediate values, but closer to the non Macaronesian populations. Seed morphology is also a taxonomic character for the two subspecies of E. lusitanica, with larger, more elongated seeds in subsp. cantabrica than in subsp. lusitanica. These results suggest a higher taxonomic distance between E. arborea and E. lusitanica than what has been considered in classical studies. © 2010, Taylor & Francis Group, LLC.