Astraceae3.html

Idaho Mountain Wildflowers

Aster (Sunflower) Family: Asteraceae

Yellow daisy-like flowers

There are so many yellow Asteraceae that it’s little wonder that botanists refer to them as "DYC" ( "damned yellow composites") because many are so similar that they are difficult to identify. So many grow in the mountains of Idaho that we can't begin to show them all. Instead we'll include representative species--in no particular order--of the more common genera, and a few other plants that hikers may encounter.

Scabland fleabane, Erigeron bloomeri A. Gray (left). As the name suggests, the scabland fleabane is grows in barren, rocky sites in the mountains and foothills. It is characterized by narrow basal leaves and naked stems that each bear a single rayless flowerhead. The species name honors California botanist, Dr. Hiram Green Bloomer (1819-1874), who collected the plant in Nevada, near Virginia City.
Line-leaf daisy, Erigeron linearis (Hook.) Piper (right). The line-leaf daisy (also known as the desert yellow fleabane) is, like the cutleaf daisy shown on the previous pag, a small plant that grows in discrete clumps. It prefers exposed gravelly slopes where it often grows in profuse numbers from late spring into the summer, as high as tree-line. As with many plants that are adapted to dry places, both leaves and stems feel brittle. The common and scientific species names describe its thin “linear” leaves.

Yellow Mules-ears, Wyethia amplexicaulis (Nutt.) Nutt. The yellow mule’s-ears (left) bears some resemblance to the arrowleaf balsam-root shown on the right. Both are large plants with showy blooms although this one prefers wet meadows rather than dry hillsides. Unlike the balsamroot, it has stemless leaves (amplexicaulis means“stem-clasping”). Further, its leaves are shiny, sometimes described as having a "varnished" appearance. Yellow mules-ears bloom in the spring, usually a week or so after the white mules-ears shown below. Boston businessman Nathaniel Wyeth (1802–1856) collected both wyethias (and other plants as well) for botanist Thomas Nuttall, while in today’s western Montana in 1833.
The Arrowleaf Balsamroot, Balsamorhiza sagittata (Pursh) Nutt., blooms in discrete clusters on hillsides where it is easily identified by its grey-green leaves and large flowers, Look for it from early in the spring well into summer, growing ever higher, its visible bright yellow patches acting almost as contour lines. Both its common and scientific names are derived from the plant's silvery arrow-shaped leaves and the roots' balsam-like odor. Native Americans are said to have eaten the plant’s roots; animals browse on its leaves. Lewis and Clark collected this plant twice, first in Oregon and then in Montana, during he spring and summer of 1806.

Hooker’s balsamroot, Balsamorhiza hookeri (Hook.) Nutt. var. hispidula (Sharp) Cronquist (left). Hooker’s balsamroot is found in many places in the West. Six varieties are recognized; some are quite localized in distribution. The variety shown here grows in south-central Idaho and south into Utah and Nevada. It is a small plant with pinnate (feather-like) leaves. Its stems and leaves are hairy, as its name hispidula (covered with stiff hairs) suggests.
Largeleaf balsamroot, Balsamorhiza macrophylla Nutt. Although the arrowleaf is by far the most prevalent species of balsamroot, there are nine other western species. The plant shown on the right, the largeleaf balsamroot (also cutleaf balsamroot), is a Great Basin species, crossing into Idaho. It is similar to the arrowleaf balsamroot, differing chiefly in the shape of its large, incised, pinnate leaves. The species name, from the Greek, reflects its common name, “large-leaf.”

The Heartleaf Arnica, Arnica cordifolia Hook. (left). The origin of the word Arnica is unknown; cordifolium means "heartshaped". The heartleaf arnica blooms from late spring into summer, usually in the shade of open woods. Its stems lie on the ground, turning upward to the flower. Arnicas typically have relatively few (8 or so), regular rays and a well defined disk. They contain arnicin, a rubefacient, and a tincture of the European plant, Arnica montana, has been used topically for centuries to treat sprains and similar conditions.
The Streambank arnica, Arnica lanceolata Nutt. (formerly Arnica amplexicaulis Nutt.). The arnica shown on the right usually grows along the banks of mountain streams--the one shown here was photographed beside a seasonal rivulet high in the White Cloud Mountains in Central Idaho. As with the yellow mule's ears shown above, the base of the leaves wraps around the stem of the plant.
Note: Most arnicas are fairly tall plants (the heartleaf arnica, and the small slender arnica are exceptions). They can usually be identified, at least generically, by having opposing leaves and relatively few-rayed flower heads.

Twin arnica, Arnica sororia Greene (left). The twin arnica takes its species name from the Latin word for “sister” presumably because two (or more) flowerheads arise from a common stem. It has a cluster of large basal leaves and smaller opposed, lanceolate, stem leaves. This is a meadow plant that grows to fairly high elevations. The twin arnica is closely related to a similar, taller and larger-leaved species (shining arnica, Arnica fulgens Pursh; not shown) that has much the same range throughout our western mountain states and Canadian provinces. Until recently the species shown here was considered to be a varietal form of the larger plant.
Spear-leaf arnica, Arnica longifolia D. C. Eaton.(right). The spear-leaf arnica is a high altitude, cluster-forming composite. It blooms in mid-August, usually close to water. The plant’s preference for sheltering rocks, its proximity to water, and its long, opposing, pointed leaves (responsible for both common and specific names) set it apart from other high altitude clustered composites.
Note: Arnicas tend to grow in their own place and this can also help in identifying them; e.g., Arnica gracilis grows high, Arnica sororia favors meadows, Arnica cordifolia is found in open forests, etc. (True of many other plants, of course, but especially for this genus.)

Slender arnica, Arnica gracilis Rydb. (left). Arnica gracilis (formerly Arnica latifolia var. gracilis) is a plant whose habit—cluster-forming, low-growing, nestled among rocks—is typical of many alpine and subalpine plants. As illustrated, it is at home on rocky ground. The rocks protect the plants and hold the sun’s heat. By looking at the plants closely, one can see that small, broadly lanceolate leaves arise opposite each other, typical of arnicas in general.

Meadow Goldenrod, Solidago lepida DC. var. salebrosa (Piper) Semple (left). The meadow goldenrod, (formerly Solidago canadensis), is distributed over much of the United States and Canada. It blooms in open places to fairly high elevations from midsummer on, usually in moist soil. The generic name Solidago was derived from two Latin words, solidus meaning “complete” and ago meaning “I make,” for the European goldenrod (S. virgaurea L.) was valued as a “vulnerary”—a substance able to heal external wounds. This plant's varietal name, salebrosa, means "rough." Although hard to see in the photograph,,the meadow goldenrod does have ray flowers, although they are tiny.
The rays are more obvious on the Mountain Goldenrod, Solidago multiradiata Aiton (right). It is also a summer blooming plant, commonly seen along our trails where the ground is moist. The plant as it occurs in Idaho is encountered at higher altitudes, although as one goes further north—in Canada, Alaska and Siberia--it grows at progressively lower elevations.

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	*Scabland fleabane, Erigeron bloomeri* A. Gray (left). As the name suggests, the scabland fleabane is grows in barren, rocky sites in the mountains and foothills. It is characterized by narrow basal leaves and naked stems that each bear a single rayless flowerhead. The species name honors California botanist, Dr. Hiram Green Bloomer (1819-1874), who collected the plant in Nevada, near Virginia City. Line-leaf daisy, Erigeron linearis (Hook.) Piper** (right). The line-leaf daisy (also known as the desert yellow fleabane) is, like the cutleaf daisy shown on the previous pag, a small plant that grows in discrete clumps. It prefers exposed gravelly slopes where it often grows in profuse numbers from late spring into the summer, as high as tree-line. As with many plants that are adapted to dry places, both leaves and stems feel brittle. The common and scientific species names describe its thin “linear” leaves.
	Yellow Mules-ears, Wyethia amplexicaulis (Nutt.) Nutt. The yellow mule’s-ears (left) bears some resemblance to the arrowleaf balsam-root shown on the right. Both are large plants with showy blooms although this one prefers wet meadows rather than dry hillsides. Unlike the balsamroot, it has stemless leaves (amplexicaulis means“stem-clasping”). Further, its leaves are shiny, sometimes described as having a "varnished" appearance. Yellow mules-ears bloom in the spring, usually a week or so after the white mules-ears shown below. Boston businessman Nathaniel Wyeth (1802–1856) collected both wyethias (and other plants as well) for botanist Thomas Nuttall, while in today’s western Montana in 1833. The Arrowleaf Balsamroot, Balsamorhiza sagittata (Pursh) Nutt., blooms in discrete clusters on hillsides where it is easily identified by its grey-green leaves and large flowers, Look for it from early in the spring well into summer, growing ever higher, its visible bright yellow patches acting almost as contour lines. Both its common and scientific names are derived from the plant's silvery arrow-shaped leaves and the roots' balsam-like odor. Native Americans are said to have eaten the plant’s roots; animals browse on its leaves. Lewis and Clark collected this plant twice, first in Oregon and then in Montana, during he spring and summer of 1806.
	*Hooker’s balsamroot, Balsamorhiza hookeri* (Hook.) Nutt. var. hispidula (Sharp) Cronquist** (left). Hooker’s balsamroot is found in many places in the West. Six varieties are recognized; some are quite localized in distribution. The variety shown here grows in south-central Idaho and south into Utah and Nevada. It is a small plant with pinnate (feather-like) leaves. Its stems and leaves are hairy, as its name hispidula (covered with stiff hairs) suggests. *Largeleaf balsamroot, Balsamorhiza macrophylla* Nutt.** Although the arrowleaf is by far the most prevalent species of balsamroot, there are nine other western species. The plant shown on the right, the largeleaf balsamroot (also cutleaf balsamroot), is a Great Basin species, crossing into Idaho. It is similar to the arrowleaf balsamroot, differing chiefly in the shape of its large, incised, pinnate leaves. The species name, from the Greek, reflects its common name, “large-leaf.”
	The *Heartleaf Arnica, Arnica cordifolia* Hook.** (left). The origin of the word Arnica is unknown; cordifolium means "heartshaped". The heartleaf arnica blooms from late spring into summer, usually in the shade of open woods. Its stems lie on the ground, turning upward to the flower. Arnicas typically have relatively few (8 or so), regular rays and a well defined disk. They contain arnicin, a rubefacient, and a tincture of the European plant, Arnica montana, has been used topically for centuries to treat sprains and similar conditions. The *Streambank arnica, Arnica lanceolata* Nutt. (formerly Arnica amplexicaulis Nutt.). The arnica shown on the right usually grows along the banks of mountain streams--the one shown here was photographed beside a seasonal rivulet high in the White Cloud Mountains in Central Idaho. As with the yellow mule's ears shown above, the base of the leaves wraps around the stem of the plant. Note:** Most arnicas are fairly tall plants (the heartleaf arnica, and the small slender arnica are exceptions). They can usually be identified, at least generically, by having opposing leaves and relatively few-rayed flower heads.
	*Twin arnica, Arnica sororia* Greene** (left). The twin arnica takes its species name from the Latin word for “sister” presumably because two (or more) flowerheads arise from a common stem. It has a cluster of large basal leaves and smaller opposed, lanceolate, stem leaves. This is a meadow plant that grows to fairly high elevations. The twin arnica is closely related to a similar, taller and larger-leaved species (shining arnica, Arnica fulgens Pursh; not shown) that has much the same range throughout our western mountain states and Canadian provinces. Until recently the species shown here was considered to be a varietal form of the larger plant. *Spear-leaf arnica, Arnica longifolia* D. C. Eaton.(right). The spear-leaf arnica is a high altitude, cluster-forming composite. It blooms in mid-August, usually close to water. The plant’s preference for sheltering rocks, its proximity to water, and its long, opposing, pointed leaves (responsible for both common and specific names) set it apart from other high altitude clustered composites. Note: Arnicas** tend to grow in their own place and this can also help in identifying them; e.g., Arnica gracilis grows high, Arnica sororia favors meadows, Arnica cordifolia is found in open forests, etc. (True of many other plants, of course, but especially for this genus.)
	*Slender arnica, Arnica gracilis* Rydb.** (left). Arnica gracilis (formerly Arnica latifolia var. gracilis) is a plant whose habit—cluster-forming, low-growing, nestled among rocks—is typical of many alpine and subalpine plants. As illustrated, it is at home on rocky ground. The rocks protect the plants and hold the sun’s heat. By looking at the plants closely, one can see that small, broadly lanceolate leaves arise opposite each other, typical of arnicas in general.

	*Meadow Goldenrod, Solidago lepida* DC.** var. salebrosa (Piper) Semple (left). The meadow goldenrod, (formerly Solidago canadensis), is distributed over much of the United States and Canada. It blooms in open places to fairly high elevations from midsummer on, usually in moist soil. The generic name Solidago was derived from two Latin words, solidus meaning “complete” and ago meaning “I make,” for the European goldenrod (S. virgaurea L.) was valued as a “vulnerary”—a substance able to heal external wounds. This plant's varietal name, salebrosa, means "rough." Although hard to see in the photograph,,the meadow goldenrod does have ray flowers, although they are tiny. The rays are more obvious on the Mountain Goldenrod, Solidago multiradiata Aiton (right). It is also a summer blooming plant, commonly seen along our trails where the ground is moist. The plant as it occurs in Idaho is encountered at higher altitudes, although as one goes further north—in Canada, Alaska and Siberia--it grows at progressively lower elevations.