Welsh's Aster
Symphytrichum welshii (Cronquist) Nesom is native to bogs, seeps and river banks in scattered disjunct locations in southern Utah, northwestern Wyoming, and a few locations in Idaho and Montana. It can be locally common. It is similar to Symphyotrichum boreale and Symphyotrichum lanceolatum. It is distinguished by having well developed rosettes on the ends of short lateral rhizomes developing later in the season; such rosettes are often present when shoots begin to flower. The phyllaries are usually spreading to squarrose when heads are fresh. Owen, Semple & Baum (2006) included the species in a multivariate study of Sy. boreale, Sy. nahanniense, and S. welshii. The species is diploid (2n=16).
Owen, E., J. C. Semple and B. Baum. 2006. A multivariate morphometric analysis of the Symphyotrichum boreale - S. nahanniense - S. welshii complex (Asteraceae: Astereae). Can. J. Bot 84: 1282–1297.
Last revised 15 May 2025 by J.C. Semple
© 2025 J.C. Semple, including all photographs unless otherwise indicated
1-6. Symphyotrichum welshii. 1. Marshy habitat, Semple 11279, Wyoming. 2. Shoots, S 112793. Shoots by river, Semple & B. Semple 11249, Garfield Co., Utah. 3. Base of stem and new shoots emerging from rhizome, Semple & B. Semple 11250, Garfield Co., Utah. 5. Heads, S & S 11249. 6. Range map JCS.