Beckwithia is a genus of plants of the family
Ranunculaceae. Most botanists consider it synonymous to a clade consisting of Ranunculus glacialis[1] and Ranunculus andersonii. B. glacialis has several distinct forms that may also be considered subspecies or closely related species. However, molecular studies have supported the placement of B. glacialis and B. camissonis within Ranunculus, distant from B. andersonii.[2][3]
Taxa
Beckwithia andersonii (A.Gray) Jeps. (= Ranunculus andersonii), Anderson's buttercup, native to the Western United States
Beckwithia glacialis subsp. glacialis (L.) Á.Löve & D.Löve (= Ranunculus glacialis), the glacier buttercup, occurring in boreal and alpine areas of Europe (including Iceland,
Jan Mayen and Svalbard)
Beckwithia camissonis (Schltdl.) Tolm. (= Ranunculus glacialis subsp. camissonis), that occurs on either side of the Bering Strait, in Siberia and in Alaska[1]
^Elvira Hörandl, et al. Phylogenetic relationships and evolutionary traits in Ranunculus s.l. (Ranunculaceae) inferred from ITS sequence analysis. Molecular Phylogenetics and Evolution 36 (2005) 305–327.
^Khatere Emadzade, et al. A molecular phylogeny, morphology and classification of genera of Ranunculeae (Ranunculaceae). Taxon. 59: 809–828 2010