Montana Field Guide

PLANTS: Well-developed shrubs of 5–80 cm height with fibrous roots and adventitious buds that can sprout after fire. Plants are pale gray to gray-green and densely tomentose and aromatic. Sources: Shultz in Flora of North America [FNA] 2006; Lesica et al. 2012

LEAVES: 1–3 cm long and deeply divided into linear or linear-oblong segments divided distally into 3 linear lobes. Sources: Shultz in FNA 2006; Lesica et al. 2012

INFLORESCENCE: Yellowish to reddish flower heads are arranged in panicles; the arrays are (5-)8-15(-35) cm by 0.5-1.0 cm (FNA 2006). Bracts that subtend the flowers are linear and entire. Sources: Shultz in FNA 2006; Lesica et al. 2012

Montana plants only belong to subspecies tripartita.

Artemisia tripartita ssp. rupicola was reported for Montana based on a specimen at the Montana State University herbarium (MONT #56976) that is mis-labeled and actually was collected in Wyoming. Subspecies rupicola is only known from Wyoming (Shultz in FNA 2006).

Sandy to clay soils of sagebrush steppe in the valleys to subalpine zones of Montana (Lesica et al. 2012).

Sagebrush in general is adapted to climates with cold winters where most precipitation falls in the winter (Meyer 2008). Shrubs in the genus Artemisia are important winter browse for ungulates (Meyer 2008). This species relies on wind for pollination and seed dispersal (Meyer 2008). Each seed is enclosed in a papery pericarp. The pericarp has mucilaginous nerves that may help the seed stick to the soil while its root penetrates (Meyer 2008).

FLOWERS
The involucre of the flower head is turbinate, 1.5-3 mm wide and 2.5–3.5 mm tall; the outer phyllaries are green and canescent while the inner phyllaries are brown to purple and glandular (Lesica et al 2012). The receptacle is glabrous. Heads are comprised of 3 to 11 disk flowers that are perfect, glandular, and have yellow to reddish corollas of 1.5–2 mm length (Lesica et al. 2012).

FRUITS
Achenes are glabrous or resinous and about 2 mm long (Lesica et al. 2012).