ALLOZYMIC AND MORPHOLOGICAL VARIATION IN ANTENNARIA (ASTERACEAE, INULEAE) FROM THE LOW ARCTIC OF NORTHWESTERN NORTH-AMERICA

Twenty-five populations of Antennaria from the low arctic of northwestern North America, including individuals that have traditionally been referred to as A. alaskana, A. angustata, A. compacta, A. densifolia, A. friesiana, A. monocephala, A. neoalaskana, and A. philonipha, were analyzed to determine the degree of divergence among populations. Sixteen putative isozyme loci were assayed to assess the amount of allozyme divergence. Morphological variation among the populations was evaluated using 30 characters. Principal components and cluster analyses were used to quantify the morphological and allozymic differences among the populations. Results indicate that four distinct groups exist among the taxa including A. densifolia, A. friesiana, s.l., A. monocephala s.l., and A. neoalaskana. Both morphological and isozyme data were concordant in indicating that the taxa have diverged from each other to the extent that they can be recognized at the rank of species. Genetic structure of the populations is comparable to other previously studied species of Antennaria and is typical of perennial herbs in general. Asexual populations of A. friesiana and A. monocephala contain an average of 3.2 clones per population, which is generally characteristic of asexual populations of Antennaria. Comparisons of diploid vs. polyploid and sexual vs. asexual populations yielded no significant differences for genetic statistics such as A, P, and H(obs) between the groups. Antennaria friesiana s.l. may contain a mixture of diploids, autopolyploids, and segmental allopolyploids.