Publication: Bull. Torrey Bot. Club. 26: 452. 1899.
selected vouchers: WTU
Notes: FNA26: "Sisyrinchium septentrionale is widespread but apparently not common in western Canada. In central Canada it intergrades with S. mucronatum, to which it appears closely related (see discussion, p. 367). It is confused also with S. montanum but can be distinguished by its very slender, very long outer spathe and nongibbous inner spathe. Fresh material will show lighter blue flowers and outer tepals with rounded apices."