C. Lefebvre et X. Vekemans, A NUMERICAL TAXONOMIC STUDY OF ARMERIA-MARITIMA (PLUMBAGINACEAE) IN NORTH-AMERICA AND GREENLAND, Canadian journal of botany, 73(10), 1995, pp. 1583-1595
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.