CYTOTAXONOMIC STUDIES ON NEW WORLD ANEMONE (SECTION ERIOCEPHALUS) WITH WOODY ROOTSTOCKS

Abstract

New World taxa of Anemone L. (section Eriocephalus Hook. f. & Thoms.) with woody rootstocks have few morphological differences on which to delimit species. With the aid of data from cytological, distributional, and hybridization studies, the following species with ternate leaves could be recognized: A. multiceps (Greene) Standl., A. multifida Poir., 2n 32, A. tetonensis Porter, 2n 32, A. stylosa Nelson, 2n 32. A. drummondii S. wats., 2n 32, and A. lithophila Rydb., 2n 48, are complexes with two or more taxa in each. All these taxa except A. multifida are restricted in distribution to the Rocky Mountains. A. multifida is a morphologically variable but cytologically homogeneous species widely distributed in both North and South America. The remaining taxa have biternate leaves and are sparingly represented in herbaria by specimens from widely separated localities. Their status has not been determined. A collection from Mt. Rainier, Wash., is diploid and one from Kittitas Co., Wash., is tetraploid.Karyotype studies indicate a close relationship among the tetraploids, A. multifida, A. tetonensis, and A. stylosa, all of which have one set of large and one set of small chromosomes. The other taxa have sets of small chromosomes only. Affinities among taxa in the A. lithophila and A. drummondii. complexes are suggested by the sharing of distinctive marker chromosomes. The European alpine A. baldensis L., 2n 16, is not related to the ternate-leaved taxa of the above complexes but a relationship with the biternate-leaved taxa may possibly exist.