Artemisia alaskana |
Artemisia tridentata |
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Alaska wormwood, alaskan sagebrush, Siberian wormwood |
big sagebrush, blue sagebrush, common sagebrush, mountain sagebrush, sagebrush |
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Habit | Perennials or subshrubs, 15–30(–60) cm (not cespitose), aromatic (caudices woody). | Shrubs, 40–200(–300) cm (herbage gray-haired), aromatic; not root-sprouting (trunks relatively thick). | ||||||||||||
Stems | 1–10, erect, gray-green, simple (suffrutescent from woody offsets), densely hairy to glabrescent. |
gray-brown, glabrate (bark gray, exfoliating in strips). |
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Leaves | basal and cauline, mostly gray-green; blades obovate, 1.5–5 × 0.5–1.5 cm, 3-lobed to 2-ternately lobed (lobes 0.5–3 mm wide, margins flat; cauline leaves smaller, sometimes entire), faces tomentose. |
persistent, gray-green; blades usually cuneate, (0.4–)0.5–3.5 × 0.1–0.7 cm, 3-lobed (lobes to 1/3 blade lengths, 1.5+ mm wide, rounded), faces densely hairy. |
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Involucres | broadly campanulate, 3.5–5 × 6–9 mm. |
lanceolate, (1–)1.5–4 × 1–3 mm. |
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Florets | pistillate 8–10; bisexual 20–45; corollas yellow, 2–2.5 mm, glabrous or glandular. |
3–8; corollas 1.5–2.5 mm, glabrous. |
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Phyllaries | ovate (margins brownish or hyaline), tomentose. |
oblanceolate to widely obovate, densely tomentose. |
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Heads | (peduncles 0 or to 30 mm) in (leafy) paniculiform to racemiform arrays 12–25 × 1–4.5 cm. |
(usually erect, on slender peduncles) in paniculiform arrays 5–30 × 1–6 cm. |
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Cypselae | ellipsoid (flattened), 1–1.5 mm, glabrous. |
1–2 mm, hairy or glabrous, glandular. |
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2n | = 18. |
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Artemisia alaskana |
Artemisia tridentata |
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Phenology | Flowering early–late summer. | |||||||||||||
Habitat | Well-drained soils, flood plains, gravel stream banks, roadsides, dry, rocky slopes, forest openings, alpine and arctic tundras | |||||||||||||
Elevation | 100–2500 m (300–8200 ft) | |||||||||||||
Distribution |
AK; BC; NT; YT |
AZ; CA; CO; ID; MT; ND; NE; NM; NV; OR; SD; UT; WA; WY; AB; BC; nw Mexico
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Discussion | As circumscribed here, Artemisia alaskana is known from northwestern North America. The type specimen of A. alaskana is atypical, with longer peduncles and narrower leaf lobes than are found in most populations. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Subspecies 4 (4 in the flora). Artemisia tridentata has undergone considerable taxonomic revision in the past century and circumscription of subspecies remains a topic of considerable controversy. Workers in the field should be aware of the morphologic variation within the subspecies across the range of the species (i.e., approximately from the Sierra Nevada in the west to the plains of the Rocky Mountains in the east). Because rangeland managers and conservationists can often identify local morphologic and chemical races based on grazing or habitat preferences of wildlife and domestic animals, some impetus exists to further subdivide the subspecies within A. tridentata at the varietal level. This treatment of the species complex remains conservative in light of the need for further study. As to chemical differences among the subspecies, aroma is often used to distinguish subspecies in the field. Volatile resins in the plants are strongly aromatic and, when crushed, leaves have very distinctive (although not easily described) aromas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 19, p. 523. | FNA vol. 19, p. 516. | ||||||||||||
Parent taxa | ||||||||||||||
Sibling taxa | ||||||||||||||
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Synonyms | A. tyrrellii | Seriphidium tridentatum | ||||||||||||
Name authority | Rydberg: in N. L. Britton et al., N. Amer. Fl. 34: 281. (1916) | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 398. (1841) | ||||||||||||
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