Artemisia vulgaris
Artemisia tridentata
armoise vulgaire, common mugwort, common wormwood, felon-herb, green-ginger, lobed wormwood, mugwort
big sagebrush, blue sagebrush, common sagebrush, mountain sagebrush, sagebrush
relatively numerous, erect, brownish to reddish brown, simple proximally, branched distally (angularly ribbed), sparsely hairy or glabrous.
gray-brown, glabrate (bark gray, exfoliating in strips).
basal (petiolate) and cauline (sessile), uniformly green or bicolor;
blades broadly lanceolate, ovate, or linear, (2–)3–10(–12) × 1.8–8 cm (proximal reduced and entire, distal pinnately dissected, lobes to 20 mm wide), faces pubescent or glabrescent (abaxial) or glabrous (adaxial).
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.
ovoid to campanulate, 2–3(–4) mm.
lanceolate, (1–)1.5–4 × 1–3 mm.
pistillate 7–10;
bisexual (5–)8–20;
corollas yellowish to reddish brown, 1.5–3 mm, glabrous (style branches arched-curved, truncate, ciliate).
3–8;
corollas 1.5–2.5 mm, glabrous.
lanceolate, hairy or glabrescent.
oblanceolate to widely obovate, densely tomentose.
in compact, paniculiform or racemiform arrays (10–)20–30(–40) × (5–)7–15(–20) cm.
(usually erect, on slender peduncles) in paniculiform arrays 5–30 × 1–6 cm.
ellipsoid, 0.5–1(–1.2) mm, glabrous, sometimes resinous.
1–2 mm, hairy or glabrous, glandular.
= 18, 36, 40, 54.
Artemisia vulgaris
Artemisia tridentata
Grown as a medicinal plant, most commonly as a vermifuge, Artemisia vulgaris is widely established in eastern North America and is often weedy in disturbed sites. Populational differences in morphologic forms are reflected in size of flowering heads, degree of dissection of leaves, and overall color of plants (from pale to dark green), suggesting multiple introductions that may date back to the first visits by Europeans. It is tempting to recognize the different forms as subspecies and varieties; the array of variation in the field is bewildering. If genetically distinct forms exist in native populations, the differences appear to have been blurred by introgression among the various introductions in North America. A case could be made for recognizing var. kamtschatica in Alaska based on its larger heads and shorter growth form; apparent introgression with populations that extend across Canada confounds that taxonomic segregation.
(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.)
1. Shrubs 100–200(–300) cm (leaf blades: lengths usually 3+ times widths); heads in relatively broad, paniculiform arrays | → 2 |
1. Shrubs 30–150 cm (leaf blades: lengths usually less than 3 times widths); heads in relatively narrow, paniculiform arrays | → 3 |
2. Involucres 1.5–2.5 × 1–2 mm; deep, well drained (usually sandy) soils in valley bottoms, lower montane slopes along drainages | subsp. tridentata |
2. Involucres 2–4 × 1–2 mm; loose, sandy soils of valleys and foothills | subsp. parishii |
3. Shrubs, 60–80(–150) cm (crowns flat-topped); heads in arrays 10–15 cm; involucres 2–3 × 1.5–3 mm; mountains | subsp. vaseyana |
3. Shrubs, 30–50(–150) cm (crowns rounded); heads in arrays 2–6(–8) cm; involucres (1–)1.5–2 × 1.5–2 mm; usually cold-desert basins and high plateaus, sometimes foothills | subsp. wyomingensis |
- Local floras:
BC, 
OR, 
WA - Local Web sites:
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
MI Flora, 
MN Wildflowers, 
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PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
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- Local floras: BC,
CA, OR, WA - Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog.
- WildflowerSearch
- iNaturalist (observations)
- USDA Plants Database
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
