Chromosome numbers for the Italian flora: 12 Author Astuti, Giovanni Orto e Museo Botanico, Universita di Pisa, Via L. Ghini 13, 56126 Pisa, Italy giovanni.astuti@unipi.it Author Bartolucci, Fabrizio https://orcid.org/0000-0001-8199-6003 Centro Ricerche Floristiche dell'Appennino (Universita di Camerino - Parco Nazionale del Gran Sasso e Monti della Laga), San Colombo, 67021 Barisciano (L'Aquila), Italy Author Conti, Fabio https://orcid.org/0000-0001-7391-6691 Centro Ricerche Floristiche dell'Appennino (Universita di Camerino - Parco Nazionale del Gran Sasso e Monti della Laga), San Colombo, 67021 Barisciano (L'Aquila), Italy Author Cera, Beatrice Dipartimento di Scienze della Terra e dell'Ambiente, Universita di Pavia, Via S. Epifanio 14, 27100 Pavia, Italy Author Giaco, Antonio Dipartimento di Biologia, Universita di Pisa, Via Derna 1, 56126 Pisa, Italy Author Orsenigo, Simone https://orcid.org/0000-0003-1694-0585 Dipartimento di Scienze della Terra e dell'Ambiente, Universita di Pavia, Via S. Epifanio 14, 27100 Pavia, Italy Author Sandroni, Luca Dipartimento di Biologia, Universita di Pisa, Via Derna 1, 56126 Pisa, Italy Author Peruzzi, Lorenzo https://orcid.org/0000-0001-9008-273X Dipartimento di Biologia, Universita di Pisa, Via Derna 1, 56126 Pisa, Italy text Italian Botanist 2021 2021-12-15 12 123 131 http://dx.doi.org/10.3897/italianbotanist.12.79031 journal article http://dx.doi.org/10.3897/italianbotanist.12.79031 2531-4033-12-123 F6F9B2653E6958CB9365220DC9F0FBDA Onopordum illyricum L. subsp. illyricum (Asteraceae) Chromosome number. 2 n = 34 (Fig. 6 ). Voucher specimen. Italy. Calabria. San Marco Argentano (Cosenza), c.da Rossillo (WGS84: 39.61343N , 16.22801E ), 16 August 2021, L. Peruzzi (seeds collected and deposited at the germplasm bank of the Department of Biology, University of Pisa; IPEN: IT-0-PI-2021-0419). 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 for 7-8 minutes. Observations. This species occurs in southern Europe, from the Iberian Peninsula to the Balkans, in Turkey, and in Syria ( Greuter 2006 +). Although several chromosome counts are available in the literature ( Moore and Frankton 1962 ; Chuksanova et al. 1968 ; Valdes 1970 ; Kuzmanova et al. 1979 ; Snogerup 1995 ), no data have been published so far for Italy, where two subspecies can be found, i.e., O. illyricum subsp. illyricum , distributed throughout south-central Italy (including Sardegna and Sicilia), and O. illyricum subsp. cardunculus (Boiss.) Arenes , which is known only for Sicilia ( Bartolucci et al. 2018 ). We confirm here the chromosome number 2 n = 34 previously reported for the species. G. Astuti, A. Giaco , L. Peruzzi Figure 6. Onopordum illyricum L. subsp. illyricum from c.da Rossillo (San Marco Argentano, Cosenza), 2 n = 34. Scale bar: 10 μm .