CHROMOSOME COUNTS OF AND NOTES ON SOME OLD WORLD ASTERS (ASTERACEAE) Almut G. Jones and Roy A, Smogor Department of Plant Biology University of Illinois, Urbana, IL 618OI In order to familiarize ourselves with the characteristics of Old World species of Aster, we acquired achenes offered in the seed lists of some botanical gardens. A portion of the material was used to obtain the chromosome counts reported below. MATERIALS AND METHODS With the exception of one population of Aster tri poll urn , all materials used in the investigation came from plants cultivated in botanical gardens. For germination, the achenes were placed on wet filter paper in Petri dishes. Some of the young seedlings were fixed and stained using standard cytological techniques. The re-maining plants were potted and grown to maturity to provide vouchers for verification of identity. For meiotic chromosome counts, buds were fixed and anthers stained, again using standard techniques. Vouchers are on deposit at ILL. RESULTS AND COMMENTS Aster alpinus L. — 2n = 18. Both meiotic and mitotic counts were obtained. Buds were collected from plants in the Botanical Garden of the University of Tlibingen ( AG J ^77 ) ; achenes came from the Conservatoire et Jardin Botanique in Geneva ( AG J 6315 ) . This species is notable for a very early flowering period (May-June) . Aster amellus L. — 2n = 18. Seed source: Cons. & Jard. Bot. Geneva ( AG J 6313 ) . The plants grown in the greenhouse are rather short -stemmed, but they clearly belong in this variable species. Aster ibericus Stev. in M.-Bieb.~ 2n = 54. Seed source: Moscow Botanical Garden (AGJ 6331 ) . The plants belong in or near A. amellus . Nees von Esenbeck placed the name in synonymy under that species (l832: 45), and the taxon was formally given varietal rank under A. amellus by De Gandolle (I836, 5: 23l) • In Komarov's Flora URSS X^5'-8?. 1959) , Tamamschjan recognized A. ibericus at species rank. Her species concept generally is very narrow but, in this case, the hexaploid chromosome number (which has been reported before by Huziwara, I962) perhaps would support treatment as a spe-cies distinct from A. amellus . However, hexaploid chromosome counts for A. amellus have also been reported (cf. Moore 1973). The plants h29
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