C.  Reynaud, ?Etude cytotaxonomique des Millepertuis du Bassin mediterraneen et des Iles Canaries. (Cytotaxonomic study of Hypericum from the western Mediterranean and the Canary Islands).?, Bull. Soc. Bot. France Lett. Bot., vol. 133, pp. 167-177 (1986) - illus., chrom. nos., 1986.