Leaves: basal and proximal cauline 4-10(-20) mm wide (cauline usually gradually reduced in size distally). Heads in dense to loose, spiciform arrays. Involucres (7-)8-11 mm. Phyllaries usually greenish. Florets (4-)6-8(-12). 2n = 20. Flowering Jul-Sep. Fields, road banks, fencerows, lake sides, wet to moist prairies and meadows, bogs, seepages, dunes, limestone and granite outcrops, sandy clays, sandy loams, moist woods, oak, oak-pine, and sweetgum flats, tamarack swamps; 50-1700 m; Ont., Que.; Ala., Ark., Conn., Del., Ga., Ill., Ind., Ky., Md., Mass., Mich., Miss., Mo., N.J., N.Y., N.C., Ohio, Pa., Tenn., Va., W.Va., Wis.
From Flora of Indiana (1940) by Charles C. Deam
This species and others of this genus are often called blazing star. In the northern half of the state this species grows generally in marshy places and in moist prairies. In the prairies it is often so abundant that it gives a rose purple color to the landscape. In the southern part of the state it is local and is found in the "flats" and in sandy soil on open, wooded slopes. The rachis of all of my plants is quite glabrous. Kriebel's no. 3958 from Greene County has the rachis closely puberulent.