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Abstract Detail



Biogeography

Allen, Geraldine [1].

Origin, diversification and geographic spread of the genus Erythronium (Tulipeae, Liliaceae).

Erythronium (the fawn-lilies, glacier lilies and trout-lilies) is the only genus of the tribe Tulipeae that has diversified extensively in the New World. Current evidence indicates that Erythronium diverged from its sister genus Amana in eastern Asia. Soon thereafter, Erythronium separated into three distinct lineages that now have separate geographic distributions in Eurasia, eastern North America and western North America. The eastern and western North American clades of Erythronium are weakly supported as sister groups, consistent with either one or two migrations of the genus from eastern Asia into North America. Erythronium has undergone its greatest diversification in western North America, where approximately 2/3 of the species occur. Although several of these are widespread in the montane west, the highest diversity of Erythronium (15+ species) is found in California. The western North American clade comprises four subclades. Two of these, one primarily subalpine and the other occurring at lower elevations, are restricted to California and adjacent Oregon. Several species in these two groups are highly localized endemics of conservation concern. Both molecular and morphological evidence support a close relationship between the subalpine and low-elevation California subclades. Nuclear (ITS) and plastid phylogenies show some discordance, suggesting that hybridization has played a considerable role in their diversification. In comparison with these two subclades, the other two western subclades are both more widespread and more distinct. The Pacific Northwest subclade (4 species) occurs at low elevations from northwestern California to southwestern British Columbia; two of the species are endemic polyploids of recent origin. The subalpine continental subclade (2 species) extends to the Rocky Mountains and central British Columbia, and includes E. grandiflorum, which has a larger geographic range than any other western species. Intraspecific genetic variation in species of both subclades is highest in southern populations, suggesting a pattern of relatively recent northward spread. Geographic origins in Asia but evidence of subsequent recent northward expansion is a pattern that has been observed in many cool-temperate to arctic-alpine taxa, reflecting the extensive effects of Pleistocene glaciation on plant geographic ranges in North America.


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1 - University Of Victoria, Department Of Biology, PO Box 1700 Station CSC, Victoria, BC, V8W 2Y2, Canada

Keywords:
Erythronium
Liliaceae
ITS
Plastid
phylogeny.

Presentation Type: Oral Paper
Session: 4, Biogeography
Location: 105/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 10:30 AM
Number: 4010
Abstract ID:766
Candidate for Awards:None


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