A NUMERICAL TAXONOMIC STUDY OF ARMERIA-MARITIMA (PLUMBAGINACEAE) IN NORTH-AMERICA AND GREENLAND

Principal components analysis, discriminant analysis, cluster analysis and two level nested analysis of variance were performed on 961 herba rium specimens of Armeria maritima covering the complete geographic ra nge of the species in North America and Greenland. Among the monomorph ic, self-compatible specimens combining coarsely reticulate pollen and papillous stigma, we recognized three subspecies. Along the Pacific c oast from California to Vancouver Island, the single taxon ssp, califo rnica is proposed, which includes the formerly described var. purpurea . In arctic and subarctic regions, ssp. sibirica, which includes var. labradorica, and sp. interior are recognized as distinct entities. The latter has a restricted distribution and can be easily distinguished morphologically owing to its glabrous calyces. The morphological varia tion between ssp. californica and ssp. sibirica is continuous and some overlap occurs. The best diagnostic characters are two ratios: sheath length to flower head width and outer involucral bract length to flow er head width. Geographic trends are obvious: a reduction in plant siz e with increasing latitude and an increase in frequency from west to e ast of hairy scapes and holotrichous calyces. The dimorphic and self-i ncompatible ssp. maritima is maintained because of its distinct breedi ng system (papillate stigma associated with finely reticulate pollen a nd smooth stigma associated with coarsely reticulate pollen). Subspeci es maritima is only found in south Greenland and some specimens are mo rphologically similar to eastern monomorphic plants.