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Idaho Mountain Wildflowers

Aster (Sunflower) Family: Compositae

White daisy-like flowers

Evermann's Fleabane, Erigeron evermannii Rydbg. (left) is a one-flowered composite characterized by a bare, furry stem and lanceolate basal leaves. It is a true mountain plant,  found only in Idaho, Montana (where it is rare), and Alberta. Its rays may be tinged with blue or pink, although ours are usually white as shown here. Barton Warren Evermann (1853-1932) was a naturalist, best known as an ichthyologist and author of Fishes of North and Middle America (1900).

Coulter’s daisy, Erigeron coulteri Porter (right). Coulter’s daisy is another one-flowered composite. It is a much taller plant, than Evermann's fleabane, and its stems are not bare but have several to many lanceolate leaves that become stemless as they ascend. There also tend to be more rayflowers—Coulter’s daisy usually has 40 to 100 rays, whereas Evermann’s daisy usually has 40 or fewer. Coulter’s daisy grows at higher altitudes, often along streams, and is present in all of the Rocky Mountain States, and in Nevada and California. John Merle Coulter, (1851-1928), for whom the plant is named started his career as botanist to a geological expedition that explored the Rocky Mountains in 1872-73. He later became an academic, holding chairs in botany at several colleges.

The Dwarf mountain  (or Cutleaf) Fleabane, Erigeron compositus Pursh (left) is a miniature daisy found at mid– to alpine elevations. Clumps, like the one illustrated on the right, bloom in mid- to late spring, usually on exposed rocky ridges. The specific name, compositus means “compound” or “made up” referring to its three-parted, or “ternate,” leaves, each made up of three leaflets. Lewis and Clark were the first to collect the cutleaf daisy . There is some debate as to whether their specimen was gathered while outward bound in the fall of 1805, or on their return journey in the spring of 1806 while on the Clearwater River in Northern Idaho. This little plant can be an attractive addition in a rock garden.

White prairie aster, Symphyotrichum falcatum (Lindl.) G. L. Nesom (right). The white prairie aster is distinguished by clusters of white flowerheads that tend to be borne on the same side of tall stems. The plants spread by short rhizomes which also contributes to their clustered appearance. Although commonly found on the plains, the plants also grow in our mountains. This one was photographed just west of Lolo Pass in north central Idaho. The name, falcatum, means “sickle-shaped.” It is not clear why it was applied to this plant.

White Mules-ears, Wyethia helianthoides Nutt. Nathaniel Wyeth (1802-1856) discovered this plant in Idaho in 1833, and it was named for him the following year by botanist Thomas Nuttall. The species name means "sunflower-like." Look at the flower disk,  and you'll see that it is made up of a myriad of tiny tubular flowerlets. Other tiny flowers along the margin bear the rays, explaining the older family name "Compositae," The common name "mules-ears" refers to the plant's large leaves. Spring-blooming white wyethias are found along seasonal streams and  in moist meadows, often in great profusion as seen on the left. The plant is found only in Idaho and contiguous states.

Interestingly, when the white Wyethia helianthoides and the yellow-flowered Wyethia amplexicaulis  (shown on the next page) grow side-by-side they may hybridize as a pale yellow-flowered form that has been given the scientific name Wyethia x cusickii Piper (right).

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