Chromosome numbers in plant taxa endemic to the Balearic Islands

Mitotic chromosome numbers are reported from 20 vascular plant taxa that are endemic to the Balearic Islands and poorly known cytogenetically. The chromosome numbers of Arenaria grandiflora L. ssp. glabrescens (Willk.) G. Lopez & Nieto Feliner (2n = 44), Dianthus rupicola Viv. ssp. bocchoriana L. Llorens & Gradaille (2n = 30), Solenopsis minuta (L.) C. Presl. ssp. balearica (E. Wimm.) Meikle (2n = 28), Romulea asumptionis Font Quer & Garcias Font (2n = 56), Scutellaria balearica Barcelo (2n = 22) and Galium balearicum Briq. (2n = 22) have been determined for the first time. A new chromosome number was found in two populations of Helictotrichon crassifolium (Font Quer) Holub (2n = c. 98) suggesting that this species is a high polyploid (14x), in contrast to an earlier report of a lower chromosome count (2n = 12x = 84). Cytogenetic observations suggest that Naufraga balearica Constance & Cannon has a diploid chromosome complement of 2n = 20, with 0–2 accessory chromosomes. The banded karyotype (chromomycin A3) of Crepis triasii (Cambess.) Fries was determined for individuals belonging to eight populations from three islands. Two chromomycin A3-positive regions were recorded in the diploid complement. These are present on the telomeric regions of the shortest subtelocentric chromosomes. This species is karyologically stable in chromosome number, karyotype and fluorochrome-banding pattern among populations from separate islands.