The genus Atriplex in Nova Scotia : taxonomy, ecology, and distribution

A biosystematic study of the genus Atriplex, based on field, herbarium, culture and cytological work delineates the taxa of this genus occurring in Nova Scotia. The study gives detailed morphological descriptions of eight taxa, and reports their chromosome numbers, breeding systems, ecology and distribution. Atriplex patula L., A. hastata L., A. littoralis L. and A. glabriuscula Edmondston, considered as varieties of A. patula by recent North American authors, are given specific rank. The confusion of these taxa by North American botanists is ascribed to the plasticity of the phenotypes, the abundance of morphologically distinctive autogamous biotypes, the presence of unrecognized species interpreted as intermediates between named taxa, the inadequate and often inaccurate treatment of the genus in North American floras, and the prevailing belief that the taxa are intergrading elements of one complex species. Two new species, one diploid and one tetraploid are reported. A hexaploid species, A. subspicata (Nutt.) Rydb., not previously recognized from eastern North America, is reported. This is the first hexaploid ever reported in the genus Atriplex. M. L. Fernald's report of A. patula var. bracteata Westerlund from Nova Scotia is shown to be based on an incorrect determination. A. glabriuscula : var. oblanceolata Vict. and Rousseau, and A. patula var. bracteata Westerlund are relegated to synonomy. The distribution of A. laciniata L. is extended.