Article

The results of karyological analyses on 32 Mediterranean taxa of the family Boraginaceae are illustrated and discussed. We investigated members of the tribe Boragineae (Cynoglottis, Phyllocara, Hormuzakia, Anchusa, Symphytum, Paraskevia, Nonea, Elizaldia, Trachystemon), Lithospermeae (Alkanna, Buglossoides, Cerinthe, Arnebia, Onosma, Echium) Cynoglosseae (Cynoglossum, Paracaryum, Solenanthus, Pardoglossum) and Eritrichieae (Lappula, Rochelia). Boragineae showed the broadest variation in base numbers, with x = 7 (Paraskevia), 8 (Anchusa, Phyllocara, Hormuzakia), 9 (Cynoglottis), 10 (Elizaldia, Symphytum, Nonea) and 15 (Elizaldia, Nonea). Such broad series is likely to reflect a complex history of chromosomal evolution. In this tribe, new reports are given for Elizaldia heterostemon and E. calycina ssp. embergeri, both endemic to Morocco, which showed 2n = 30 and 2n = 20, respectively. Chromosomes of these taxa and Nonea vesicaria (also 2n = 30) showed heterochromatic segments and secondary constrictions, indicating a probable phylogenetic relationship. Tribe Cynoglosseae showed the lowest variation, with only x = 12 as haploid number in Cynoglossum, Omphalodes, Paracaryum, Pardoglossum and Solenanthus. Radiation and evolution of new forms in this group seem to have involved minor karyological rearrangements with respect to Boragineae and Lithospermeae, also in terms of changes of chromosome morphology and ploidy levels.