Tanacetum balsamita
Sp. Pl. 2: 845. 1753.
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.
Phenology: Flowering Aug–Sep.
Habitat: Disturbed sites, abandoned plantings
Elevation: 0–1800 m
Distribution
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.
Discussion
Selected References
None.