Longleaf Wormwood

Artemisia longifolia appears to be more salt-tolerant than most species of the genus. It is closely related to A. ludoviciana.

Perennials, 20–80 cm (not cespitose), pleasantly aromatic (fibrous-rooted, rootstocks relatively short, horizontal, layered stems sometimes sprouting). Stems 3–20+, erect, gray-green, usually simple, sometimes branched (bases woody), densely tomentose. Leaves cauline, bicolor (white and green); blades linear to lanceolate, 3–12 × 1 cm, margins usually entire, sometimes toothed or lobed, faces densely tomentose (abaxial) or glabrate (adaxial). Heads (peduncles 0 or to 2 mm) in mostly racemiform arrays 8–13 × 1–2 cm. Involucres campanulate, 4–5 × 4–5 mm. Phyllaries ovate-lanceolate (margins hyaline), densely to sparsely tomentose. Florets: pistillate 3–10; bisexual 8–26; corollas pale yellow, 1–2 mm, sparsely glandular. Cypselae ellipsoid, 0.5–0.8 mm, glabrous. 2n = 36.

Artemisia falcata Rydberg; A. ludoviciana Nuttall var. integrifolia A. Nelson; A. natronensis A. Nelson; A. vulgaris Linnaeus subsp. longifolia (Nuttall) H. M. Hall & Clements; A. vulgaris var. longifolia (Nuttall) M. Peck

Artemisia longifolia Nutt. Gen. 2 : 142. 1818
Arlemisia integrifolia Vurs^ii.VX. Am. Sept. 520. 1814. t^ot A. integrifolia'L,. 1753. Artemisia ludoviciana integrifolia A. Nelson, First Rep. Fl. Wyo. 138. 1896. Artemisia natronensis A. Nelson, Bull. Torrey Club 26: 485. 1899.
A perennial, with a horizontal rootstock; stem 3-10 dm. high, white-tomentose; leaves linear or linear-lanceolate, 6-15 cm. long, often revolute, loosely floccose or in age glabrate above, white-tomentose beneath, sometimes caudate-attenuate; heads many in a narrow panicle, mostly erect and peduncled; involucre rounded-campanulate, 4-5 mm. high, 3-4 mm. broad, densely tomentose; bracts about 12, in about 3 series; outer bracts ovate, acute, fully half as long as the innermost; irmer bracts oval, acute; ray-flowers 5-8; corollas nearly 2 mm. long; disk-flowers 15-25; corollas light-yellow, nearly 3 mm. long; achenes nearly 2 mm. long. {A. natronensis is a form with somewhat broader and shorter leaves.)
Type locality: Banks of the Missouri, at the confluence of White River, South Dakota.
Distribution: Manitoba to Nebraska, Oregon, and Washington.

Artemisia longifolia is North American species in the daisy family, known by the common name long-leaved sage or longleaf wormwood. It is native to western Canada (Manitoba, Saskatchewan, Alberta, British Columbia) and the north-central United States (Montana, the Dakotas, Minnesota, Wyoming, and Colorado with a few isolated populations in Oklahoma).

Artemisia longifolia is a perennial up to 80 cm (32 inches) tall, usually not forming clumps. Leaves are longer and narrower than for most related species, up to 12 cm (5 inches) long. The species grows in barren areas, in grasslands, and in alkaline flats in the high plains. It is completely deciduous unlike many related species in Artemisia.