Symphyotrichum firmum

Glossy-leaved Aster

Symphyotrichum firmum (Nees) G. L. Nesom is a little known species hiding amongst individuals of Sy. puniceum in eastern North America (Brouillet et al. 2006; FNA).  The species has been treated as a synonym of Sy. puniceum (e.g. Semple et al. 2002; 3rd ed. of the Asters of Ontario), although the morphological study by Warners & Loughlin (1999) presented strong evidence that Aster firmus Nees was distinct in multiple ways from plants of A. puniceum L. in local mixed populations in Michigan.  The problem is that the differences are not absolute, e.g.s 1) lighter colored and even white rayed S. puniceum are occasionally encountered, 2) while mostly hairless, some individuals of Sy. firmum can have hairy stems, but the hairs tend to be in lines rather than more evenly dispersed as in Sy. puniceum, 3) the thinner elongated rhizomes of Sy. firmum are readily distinct from the thicker short branched rootstocks of Sy. puniceum but most herbarium collections of both species lack lower stems and root systems.

Key to Symphyotrichum firmum and Symphyotrichum puniceum (modified from key of Warners & Loughlin 1999)

Stems glabrous, occasionally hispidulous in lines; abaxial stem leaf mid-vein glabrous; capitulescence dense, leafy; heads with white to pale lavender ray florets; shoots arising singly from elongate rhizomes ...... Symphyotrichum firmum

Stems densely hispid pubescent, usually purplish; abaxial stem leaf midvein moderately to densely pubescent; inflorescence widely spreading and heads with lavender to purple ray florets; shoots often found in clumps of 2–6 arising from a persistent stout caudex  ... Symphyotrichum puniceum

All images were taken of a single shoot growing in a swampy woods in Erbsville, Ontario in 2005.  These were taken on a short local field trip to find a more glabrous individual of "Sy. puniceum" in a population that included hairy typical Sy. puniceum; the plant readily keyed out to Sy. firmum.  The full distribution of Sy. firmum is yet to be determined and no range map is presented here.