Perennials, 40-60(-100) cm (mat-forming), aromatic. Stems gray-green (sometimes woody proximally), densely canescent to glabrescent (hairs appressed). Leaves deciduous, gray-green; blades broadly ovate, 3-8 × 1-4 cm, mostly pinnately lobed (basal 2-3-pinnatifid, lobes obovate), faces densely canescent. Heads (nodding) in open (diffusely branched), paniculiform arrays 10-20(-35) × (2-)10-13(-15) cm. Involucres broadly ovoid, 2-3 × 3-5 mm. Phyllaries gray-green, densely sericeous. Florets: pistillate 9-20; bisexual 30-50; corollas 1-2 mm, glandular. Cypselae (± cylindric, slightly curved, obscurely nerved), ± 0.5 mm, glabrous (shiny). 2n = 18. Flowering mid summer-fall. Widely cultivated, persisting from plantings, disturbed areas; 0-1000 m; introduced; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask.; Calif., Colo., Conn., Idaho, Ill., Ind ., Iowa, Kans., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Oreg., Pa., R.I., S.C., S.Dak., Tenn., Utah, Vt., Wash., Wis., Wyo.; Europe. Artemisia absinthium provides the flavoring as well as the psychoactive ingredient for absinthe liquor, a beverage that is illegal in some markets. Known as a powerful neurotoxin, absinthe in large quantities is addictive as well as deadly. The species is popular in the horticultural trade. Prized by gardeners for its gracefully scalloped leaves and gray-green foliage, it creates an attractive and winter-hardy flower border.
Perennial herb or near-shrub 4-10 dm, the stem finely sericeous or eventually glabrate; lvs silvery-sericeous, sometimes eventually subglabrate above, the lower long-petiolate and 2-3 times pinnatifid, with mostly oblong obtuse segments 1.5-4 mm wide, the blade rounded-ovate in outline; upper lvs progressively less divided and shorter-petiolate, the segments often more acute; infl ample, leafy; involucre 2-3 mm; receptacle beset with numerous long white hairs between the fls; achenes nearly cylindric, but narrowed to the base and rounded at the top; 2n=18. Fields and waste places; native of Europe, now established across n. U.S. and adj. Can., throughout our range. July-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.