Similar to no. 20 [Aster ericoides L.], but smaller, seldom over 6 dm, with fewer and larger heads; heads solitary or clustered at the ends of the not at all secund branches, or the stem scarcely branched and the infl subracemiform; invol 5-7 mm, its bracts seldom much imbricate, the outer often acute as well as the inner; rays 20-35, 4-8 mm; disk-fls (14-)18-30; 2n=10, 20, 30. Prairies and other open places; Mack., Yukon, and e. Alas. s. to w. Minn., Io., Tex. and Ariz. Typical A. falcatus is northern, tufted, and not rhizomatous. More or less rhizomatous plants, commoner with us, have been segregated as var. commutatus (Torr. & A. Gray) A. G. Jones. (A. commutatus)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.