Symphyotrichum laeve (Aster laevis) smooth blue aster Asteraceae ASLA3; Bx, cm (planted), pb; Q, cu, ft, i; K, do; R, c, k, lp, ml (Torrey 2017), r, ro, ty;

  

Aster laevis

Aster laevis.M. B. Gargiullo.(ca 2010).

Symphyotrichum laeve is a perennial herb 30-100 cm tall, from a root crown or short rhizome, stem smooth, somewhat bluish-waxy. 

Leaves alternate, basal leaves with winged stalk, middle leaves clasping stem, blade 3-10 cm long, 1-2.5 cm wide, tip pointed, base usually lobed, surface smooth, slightly fleshy, waxy blue-green, veins obscure, margin entire to finely toothed, leaves of inflorescence small, bract-like; inflorescence open, branched. 

Flowers in small, daisy-like heads, rays blue to violet, 15-30, 0.8-1.5 cm long, disc flowers yellow, turning red-purple, bracteate base 0.5-0.9 cm long, bracts in several rows with green tips; blooming Aug.-Oct. 

Fruit dry, 1-seeded, achene, with tuft of tan hairs (pappus), wind dispersed. 

Wetland status: UPL. 

Frequency in NYC: Occasional. 

Origin: Native. 

Habitat: Open areas, dry sandy soil, fill. Tolerates part-shade. 

Notes: Susceptible to an orange colored rust fungus (Coleosporium asterum), especially late in season (University of Minnesota Extension.http://blog-yard-garden-news.extension.umn.edu/2013/09/rust-fungi-infect-fall-blooming.html.; Gargiullo personal observation). Host to larvae of the pearly crescent butterfly, Phycoides tharos Nymphalidae, (Tallamy 2003; Pyle 1981).