|Viola pluviae Marcussen, H.E. Ballard & Blaxland|
in Blaxland, Ballard & Marcussen, 2018.
chasmogamous flower. Washington: Issaquah, May 1996.
Photos by Kim Blaxland, botanikim.com.
As hirtherto circumscribed, the allo‐octoploid Viola palustris L. exists in three distinct races in North America. The race occurring in the Pacific Northwest of North America has previously been shown to have originated by polyploidy from a different set of ancestral tetraploids than the nominal, Amphi‐Atlantic race. These two races differ also in a number of morphological characters, which has been a historical source of confusion. We here propose a new name for the western plants, Viola pluviae Marcussen, H.E. Ballard & Blaxland, and typify it with a specimen collected near Mt Rainier (USA, Washington) with known chromosome number. Distribution, phylogenetic history and taxonomy are discussed and an updated morphological key to the Pacific Northwestern species of Viola is presented.
Key words: Viola palustris, bog violet, Plagiostigma, allopolyploid, Pleistocene
Viola pluviae Marcussen, H.E. Ballard & Blaxland sp. nov.
Etymology: Viola pluviae literally translates to ‘rain’s violet’ in reference to the rainy, coastal climate where it occurs. The pun on the name of the type locality, Mt Rainier, is of course entirely unintended.
Distribution: Viola pluviae is widespread along the Pacific coast from northern California to southern Alaska, the Cascades, and parts of the Rocky Mountains (Montana, Idaho).
Kim Blaxland, Harvey E. Ballard and Thomas Marcussen. 2018. Viola pluviae sp. nov. (Violaceae), A Member of Subsect. Stolonosae in the Pacific Northwest Region of North America. Nordic Journal of Botany. 36(9) e01931 DOI: 10.1111/njb.01931