Willowleaf Aster, Willow Aster
Symphyotrichum praealtum (Poir.) Nesom occurs in wet, loamy soils, wet prairies or meadows, lake and stream shores, oak savannas, open woods or thickets, fields, moist banks, ditches, roadsides, recent clearingsfrom Maine to southeastern South Dakota south to Florida and Texas and into northern Mexico (Brouillet et al. 2006; FNA). The Willowleaf Aster is most likely confused with Sy. lanceolatum and Sy. simmondsiibut is distinguished by its generally stiffer leaves with that are progressively reduced distally, have adaxial waxy faces, and abaxial faces with well-marked, isodiametric areoles (vein pattern). Plants in the northeastern portion of the range (var. angustior) have been reported to be octoploid 2n=64; plants from elsewhere in the range have been reported to be mostly tetraploid 2n=32 with a few hexaploid 2n=48 and octoploid 2n=64 reports for Texas.
G. L. Nesom (1994b, 1997) and J. C. Semple et al. (2002) recognize several varieties within the species: var. praealtum [synonyms: Aster coerulescens DC., A. praealtus var. coerulescens (DC.) A. G. Jones, A. praealtus var. imbricatior Wiegand]; var. angustior(Wieg.) G. L. Nesom [synonym: A. praealtus var. angustior Wieg.]; var. nebraskense (Britton) G. L. Nesom [synonym: A. praealtus var. nebraskensis Britt.); var. subasperum (Lindley) G. L. Nesom [synonyms: A. praealtus var. subasper (Lindl.) Wieg., A. subasperLindl.]; and var. texicola (Wieg.) G. L. Nesom (synonym: A. praealtus var. texicola Wieg.]. Some of these varieties deserve recognition (bold), but the validity of others needs confirmation via a detailed multivariate morphometric or DNA sequence analysis of the species and relatives.
Revised 6 May 2021 by J.C. Semple
© 2021 J.C. Semple, including all photographs unless otherwise indicated
