Artemisia arbuscula |
Artemisia globularia |
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black sagebrush, dwarf sagebrush, little sagebrush, low sagebrush |
purple wormwood |
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Habit | Shrubs, 10–30(–50) cm, aromatic; root-sprouting. | Perennials, (3–)5–16(–30) cm (cespitose), faintly aromatic (not rhizomatous, taproots stout, caudices simple or branched, proximal branches clothed with persistent leaf bases). | ||||||||||||
Stems | gray-green to brown, glabrate (diffusely branched from bases, brittle). |
1–5, erect, whitish gray, densely tomentose. |
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Leaves | (vegetative stems) persistent, gray-green; blades broadly to narrowly cuneate, 3–10 × 2–5 mm, lobed (lobes 3, oblong-linear, to 1/3 blade lengths, mostly 1–3 mm wide, flat, obtuse, laterals sometimes 2–3-fid; leaves on flowering stems deciduous, blades narrowly cuneate, deeply 3-lobed), faces densely hairy (not sticky resinous). |
mostly basal (cauline 1–4), greenish to whitish green; blades (basal) 1–4.5 × 0.6–1.5 cm, 1–2-ternately to palmately lobed (flowering-stem blades 3-lobed), faces sparsely hairy. |
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Involucres | campanulate or globose-ovoid, (1.5–)2–4(–5) × 1.5–4.5 mm. |
campanulate or hemispheric, 3.5–6 × 6–11 mm. |
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Florets | 4–6(–10); corollas 1.5–2 mm, glabrous. |
pistillate 9–10; bisexual 20–30; corollas yellow or reddish black, 2–3 mm, sometimes glandular. |
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Phyllaries | (margins green) ovate (outer) to oblong, pubescent or tomentose. |
lanceolate (margins brown), pilose. |
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Heads | usually borne singly, rarely (1–4, erect, mostly sessile, in pedunculate clusters) in spiciform or paniculiform arrays 2–9 × 0.5–2 cm (branches slender). |
(2–20, peduncles 0 or to 25 mm) in subcapitate to capitate arrays 2–3 × 2–3 cm. |
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Cypselae | (light brown) 0.7–0.8 mm, resinous. |
oblong, 1.5–2.5 mm, (apices flattened) glabrous. |
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Artemisia arbuscula |
Artemisia globularia |
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Distribution |
CA; CO; ID; MT; NV; OR; UT; WA; WY
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AK; YT; Asia |
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Discussion | Subspecies 3 (3 in the flora). Artemisia arbuscula is one of the more perplexing species in the Tridentatae complex. Anatomic and morphologic characteristics suggest multiple hybrid origins for the subspecies. Deciduous leaves of flowering stems in plants that otherwise have persistent leaves suggest a hybrid origin involving plants of the A. tridentata and A. cana lineages. In most instances, populations of A. arbuscula appear to be reproductively stable. The disposition of Artemisia arbuscula subsp. longicaulis Winward & McArthur (with 2n = 54) has not been determined. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Subspecies 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 19, p. 511. | FNA vol. 19, p. 525. | ||||||||||||
Parent taxa | Asteraceae > tribe Anthemideae > Artemisia > subg. Tridentatae | Asteraceae > tribe Anthemideae > Artemisia > subg. Artemisia | ||||||||||||
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Subordinate taxa | ||||||||||||||
Synonyms | A. tridentata subsp. arbuscula, A. tridentata var. arbuscula, Seriphidium arbusculum | Ajania globularia, A. norvegica subsp. globularia | ||||||||||||
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 398. (1841) | Chamisso ex Besser: Nouv. Mém. Soc. Imp. Naturalistes Moscou 3: 64. (1833) | ||||||||||||
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