Perennials, 30-80(-120) cm. Stems 1, erect, simple or branched (strigose, glabrate). Leaves basal and cauline; petiolate (proximal) or sessile (distal); blades (basal and proximal cauline) mostly elliptic to oblong, 10-20 × 2-8 cm, usually not pinnately lobed (sometimes with 1-4+ lateral lobes near bases), margins ± crenate, faces usually silvery strigose or sericeous (at least when young), glabrescent, ± gland-dotted. Heads (3-)10-60+ in corymbiform arrays. Involucres (3-)5-8(-10) mm diam. (phyllaries 40-60+ in 3-4+ series, tips usually ± dilated). Receptacles flat to convex. Ray florets usually 0 [sometimes 12-15, pistillate, fertile; corollas white, laminae 4-6+ mm]. Disc corollas ca. 2 mm. Cypselae ± columnar, 1.5-2 mm, 5-8-ribbed (with non-mucilaginous glands); pappi coroniform, 0.1-0.4 mm (entire or ± toothed). 2n = 18, 54. Flowering Aug-Sep. Disturbed sites, abandoned plantings; 0-1800 m; introduced; N.S., Ont., Que., Sask.; Calif., Colo., Conn., Del., Idaho, Ill., Ind., Kans., Maine, Md., Mass., Mich., Mo., Mont., Nev., N.H., N.Y., Ohio, Oreg., Pa., R.I., S.Dak., Utah, Vt., Wash., Wis., Wyo.; Asia.
From Flora of Indiana (1940) by Charles C. Deam
This species possesses medicinal qualities and for this reason was formerly much cultivated in gardens, from which it has occasionally escaped. There are five reports for the state. When once established, it is able to maintain itself.
Indiana Coefficient of Conservatism: C = null, non-native
Coarse, fragrant perennial 5-15 dm; stem strigose above; lvs silvery-strigose or subsericeous when young, later ±glabrate, crenate, sometimes with a few reduced basal pinnae, the basal with elliptic or broadly oblanceolate blade 10-25 נ2.5-8 cm on a petiole of ca equal length, the cauline smaller, numerous, sessile or nearly so, seldom over 10 cm; heads numerous in a corymbiform infl, the disk 4-7 mm wide; rays wanting, or occasionally present, white, and well under 1 cm; 2n=18, 54. Roadsides and other waste places; native of s. Europe and the Orient, occasionally intr. or escaped in our range. Aug.-Oct. Generic position uncertain. (Tanacetum b.; Balsamita major)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.