Artemisia annua |
Artemisia stelleriana |
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annual wormwood, armoise annuelle, sweet annie, sweet sagewort |
armoise de Steller, beach wormwood, dusty miller, oldwoman, Steller's wormwood |
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Habit | Annuals, 30–200(–300) cm, sweetly aromatic. | Perennials, (15–)20–60(–70) cm (mat-forming), sometimes faintly aromatic (rhizomes creeping, relatively thin). |
Stems | mostly 1, erect, green, turning to reddish brown with age, simple (smooth or ribbed), glabrous or sparsely hairy. |
1–3, erect or ascending, white, simple (stout), densely tomentose to floccose. |
Leaves | cauline, bright green; blades triangular to broadly ovate, 2–5(–10) × 2–4 cm, 2–3-pinnatifid (lobes relatively narrow, ± toothed), faces glabrous, gland-dotted. |
basal and cauline (petiolate), silver-gray; blades oblanceolate, (proximalmost) 3–10 × 1–5 cm, pinnatifid (lobes relatively broad, rounded; distal leaves, on flowering stems, smaller), faces densely tomentose. |
Involucres | globose, 1.5–2.5 × 1.5–2.5 mm. |
broadly campanulate, 5–8 × 6–7 mm. |
Florets | pistillate (0–)10–20; bisexual 18–24; corollas pale yellow (broadly campanulate), 0.5–1 mm, glabrous. |
pistillate 12–16; bisexual 25–30; corollas yellow (narrow or tubular), 3.2–4 mm (unusually large), glabrous or sparsely hairy (style branches prominent, erect, blunt). |
Phyllaries | (green) lanceolate, glabrous. |
broadly lanceolate, tomentose. |
Heads | (nodding, peduncles 2–5 mm) in open, (diffusely branched, leafy) arrays 15–30(–40) × 10–20 cm. |
(erect or spreading, peduncles 0 or to 3 mm) in dense, paniculiform, racemiform, or spiciform arrays 8–20 × 2–4 cm. |
Cypselae | oblong (flattened), 0.3–0.8 mm, glabrous. |
(dark brown) narrowly oblong-linear (slightly flattened, smooth), 3–4 mm, glabrous. |
2n | = 18. |
= 18. |
Artemisia annua |
Artemisia stelleriana |
|
Phenology | Flowering late summer–fall. | Flowering early spring–fall. |
Habitat | Moist waste areas, sandy soils | Sandy soils, coastal strand |
Elevation | 0–2000 m (0–6600 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; AR; AZ; CA; CO; CT; DC; DE; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MS; MT; NC; NE; NH; NJ; NY; OH; OK; OR; PA; TN; TX; VA; VT; WA; WI; WV; WY; NB; ON; QC; Eurasia [Introduced in North America]
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AK; CT; DE; FL; LA; MA; MD; ME; MI; MN; NC; NH; NJ; NY; OH; PA; RI; VA; VT; WA; WI; WV; NB; NF; NS; ON; PE; QC; SPM; n Europe; e Asia (Japan, Kamchatka)
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Discussion | Widely cultivated for aromatic oils, Artemisia annua often persists in gardens, becoming naturalized in moist-temperate areas (especially in eastern United States). Reports of naturalization may be exaggerated (reported for Prince Edward Island, but not established). The systematic placement of this species appears to align most closely with species of the Eurasian subg. Seriphidium (L. E. Watson et al. 2002). Molecular evidence suggests that the Artemisia annua lineage may be ancestral to woody species in the Old World. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Artemisia stelleriana is apparently native along the western tip of the Aleutian islands (D. F. Murray, pers. comm.). It is an attractive ornamental and, in parts of its range in the flora area, it appears to have escaped from cultivation and is naturalized in beach dunes and other sandy habitats. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 19, p. 523. | FNA vol. 19, p. 532. |
Parent taxa | Asteraceae > tribe Anthemideae > Artemisia > subg. Artemisia | Asteraceae > tribe Anthemideae > Artemisia > subg. Artemisia |
Sibling taxa | ||
Synonyms | A. chamomilla | |
Name authority | Linnaeus: Sp. Pl. 2: 847. (1753) | Besser: Nouv. Mém. Soc. Imp. Naturalistes Moscou 3: 79, plate 5. (1834) |
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