Chromosome Studies in the Alpine and Subalpine Floras of Mexico and Guatemala

B eaman , J. H. (Michigan State U., East Lansing), D. C. D. D e J ong , and W. P. S toutamire . Chromosome studies in the alpine and subalpine floras of Mexico and Guatemala. Amer. Jour. Bot. 49(1): 41–50. Illus. 1962.—Chromosome counts of 101 collections representing 69 species in 42 genera and 22 families have been obtained. Counts are reported for the first time in 59 species and 2 genera ( Oreobroma and Villadia ). Counts establishing new basic numbers were found in Draba, Lithospermum , and possibly in Arenaria. Where pertinent, the chromosomal data are related to previous taxonomic or chromosomal investigations. Chromosome numbers are now known in nearly half of the species in the alpine flora of Mexico.