CYTOLOGICAL STUDIES IN THE GENUS ERIGERON

Abstract

The literature relating to the chromosome numbers in the genus Erigeron has been reviewed, and all reported numbers are given. The chromosome number for E. breweri var. porphyreticus (Jones) Cronquist, 2n = 18; E. divergens var. cinereus A. Gray, 2n = 27; E. glabellus var. glabellus Cronquist, 2n = 36; E. glabellus var. pubescens (Hook.) Cronquist, 2n = 36; E. hyssopifolius Michx., 2n = 18; E. quercifolia Lam., 2n = 36; E. simplex Greene, 2n = 27; E. strigosus var. beyrichii (Fisch. & Mey.) A. Gray, 2n = 27; and E. vernus T. & G., 2n = 18 are new determinations. Different numbers from those previously reported have been found for E. pulchellus Michx., 2n = 27, and E. strigosus (Muhl.) Willd., 2n = 36. Chromosome counts over a large area of their distribution have been made for E. annuus (L.) Pers., E. pulchellus Michx., E. philadelphicus L., and E. strigosus (Muhl.) Willd.