Onobrychis alba (Waldst. & Kit.) Desv. subsp. echinata (Guss.) P.W.Ball

Chromosome number.

2 n = 14 (Fig. 2)

Voucher specimen.

Italy. Puglia. Gravina di Leucaspide (Statte, Taranto) (WGS84: 40.566319N, 17.190559E), gariga, 150 m s.l.m., 25 June 2019, L. Bernardo & G. Maiorca (CLU).

Method.

Squash preparations were made on root-tips obtained from germinating seeds. Root tips were pre-treated with 0.4% colchicine for 3 hours and then fixed in Carnoy fixative solution for 1 hour. After hydrolysis in HCl 1N at 60 °C, the tips were stained in leuco-basic fuchsine.

Observations.

Onobrychis alba subsp. echinata is endemic to Southern Italy, where it occurs in Puglia, Basilicata, and Calabria. Cenci et al. (2000) reported a chromosome number 2 n = 2 x = 14 for all the Italian subspecies of O. alba, but without providing any information about the source of these data. Therefore, we report here the first count safely attributable to a well-defined population of O. alba subsp. echinata . This count is, however, in accordance with Cenci et al. (2000). Pedrotti and Cortini Pedrotti (1971) reported the same chromosome number for a population of O. alba subsp. alba from Umbria. Our count supports the differentiation of this taxon from O. calabrica Širj ., a tetraploid species with 2 n = 4 x = 28 chromosomes, endemic to a small area in south-eastern Calabria (Bernardo et al. 2018).

G. Astuti, L. Bernardo