Annual or biennial. Stems erect, simple or branched, 20–90 cm. Herbage glabrous, inodorous. Leaves basal and cauline, petiolate; blades oblanceolate, 2–15 cm long, 1 to 2 times pinnately divided into dentate, lanceolate segments. Inflorescence compound-spiciform, bracts linear or lobed. Involucre hemispheric, 2–3 mm high; phyllaries green to purple, glabrous; receptacle glabrous. Disk flowers 20 to 60, the outer female, glandular; corolla ca. 1 mm long; yellow. Achenes glabrous, up to 1 mm long (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Montana has about 19
Artemisia species, generally referred to as sagebrush, sagewort, mugwort, and wormwood. Of these 8 species are well-developed shrubs, and the remainder are woody at their base (sub-shrubs) or herbaceous. A technical field guide should be used to identify
Artemisia species.
Some of the Artemisia species that have flowerheads without hairy receptacles and with marginal pistillite and central perfect florets:
Biennial Wormwood -
Artemisia biennis, native
* Plants: Annual or biennial, herbaceous forb. Little to not odorous. Hairs lacking (glabrous).
* Root: Taproot.
* Leaves: Greenish, and oblanceolate in outline. Divided into dentate, lanceolate segments and coarsely toothed
White Sagebrush -
Artemisia ludoviciana, native, desirable
* Plants: Perennial, herbaceous forb. Aromatic. Hairs short and soft (pubescent).
* Root: Rhizomatous.
* Leaves: Gray-greenish, linear lanceolate, with entire, lobed, or deeply-lobed margins - depending upon the subspecies which intergrade.
Common Wormwood -
Artemisia vulgaris, non-native, occasionally escapes cultivation
* Plants: Perennial, herbaceous forb. Faintly to not aromatic. Hairs absent to sparse.
* Root: Rhizomatous.
* Leaves: Uniformly green or bicolored (green upper side and whitish lower side, lanceolate, ovate, or linear, with deep-pinnately divided lobes. Main stem leaves with 1-2 pairs of lobes on the petiole!
One of three Artemisia species that have flowerheads with hairy receptacles, marginal pistillate florets, and perfect central florets:
Absinth Wormwood -
Artemisia absinthium, non-native, invasive, undesirable
* Plants: Robust, herbaceous, perennial forb. Aromatic. Hairs dense, fine, gray-white hairs (canescent).
* Root: Taproot.
* Leaves: Gray-greenish, and ovate in outline. Pinnately divided 2-3 times into linear-lanceolate segments, at least 2 mm wide.
Fringed Sage -
Artemisia frigida, native
* Plants: Short, perennial sub-shrub. Aromatic. Hairs dense, soft,
andinterwoven (tomentose) to canescent.
* Root: Branched caudex.
* Leaves: Gray-greenish, and oblong. Divided 2-3 times into linear segments, about 1 mm wide.
Alpine Sagebrush -
Artemisia scopulorum, native
* Plants: Smaller, herbaceous, perennial forb. Hairs stiff, straight, sharp,
and appressed (strigose) to canescent.
* Root: Branched caudex.
* Leaves: Gray-greenish, and ovate in outline. Divided 2 times into linear-oblanceolate segments about 1 mm wide.
