The Canada Aster, Great Northern Aster, Western Bog Aster, aster modeste
Canadanthus Nesom includes a single x=9 species (2n=18) of North American aster first described as Aster modestus Lindl. Nesom (1994) placed the species in its own genus Canadanthus as Canadanthus modestus (Lindl.) G.L. Nesom. Xiang and Semple (1996) found it to be basal within Symphyotrichum in the broadest sense based on cpDNA RFLP analysis. This was confirmed in Brouillet et al.(2001). Semple (in Semple et al.1996) treated it as Aster modestus. Nesom's combination was accepted by Semple et al.(2002) and is the name used for the species in Flora North America (Brouillet 2006 FNA).
1-2. Canadanthus modestus, Semple & Brouillet 4294, Alberta. 1. Upper stem. 2. Flowering heads. 3. Mature fruit, Semple & Brouillet 7008, Broadwater Co., Montana.
Brouillet, L. 2006. Canadanthus G.L. Nesom. pp. 458--459. In Flora North America Editorial Committee, North America. Vol. 20. Asteraceae, Part 2. Astereae and Senecioneae. Oxford University Press, New York.
revised 27 March 2025 by J.C. Semple
© 2025 J.C. Semple, including all photographs unless otherwise indicated