Machaeranthera tenacetifolia, Tansyleaf Tansyaster
Scientific Name: Machaeranthera tenacetifolia
Common Name: Tansyleaf Tansyaster
Also called: Takhoka-daisy, Tanseyleaf Aster and Tanseyleaf Goldenweed
Family: Asteraceae, Sunflower Family
Synonyms: (Aster tanacetifolius, Machaeranthera coronopifolia, Machaeranthera parthenium)
Duration: Annual or biennial.
Size: Up to 2 feet
Growth Form: Forb/herb; erect; 1 or more stems, multiple long rangy branches; covered with fine short minute hairs (puberulous), sticky (glandular).
Leaves: Green or greenish-gray; fern-like 3 inches or more, hairy; glandular, sticky; lower leaves deeply pinnately dissected, upper leaves linear, tiny spines on tips of leaves.
Flower Color: Bright blue-purple or lavender; radiate heads; showy; delicate narrow ray flowers; ligulate 12-40, disk flowers numerous; yellow, bracts below flower heads in 3 to 5 whorls with elongated tips spreading to curving outward; fruit is an achene.
Flowering Season: June to October, responds to summer monsoon rainfall. Blooms earlier in California; March to October.
Elevation: 1,000 to 8,000 feet.
Habitat Preferences: Various habitats across a wide range, Rocky Mountains and Great Plains to lower and upper Sonoran Desert, pine forests, chaparral, pinyon-juniper and grassy areas, fields, roadsides, streambeds and disturbed areas or waste areas.
Recorded Range: In the United States, native to the west and central United States, Alberta, Canada. Species east of the Mississippi likely introduced. Also found in northern and central Mexico. In the north half and southern part of Arizona.
U.S. Weed Information: No data available.
Invasive/Noxious Weed Information: No data available.
Wetland Indicator: No data available.
Threatened/Endangered Information: No data available.
Comments: Like many asters in the United States, Tansyleaf Tansyaster is common in its preferred range. It is similar in appearance to other asters and most particularly similar to the closely related Hoary Tansyaster, Dieteria canescens. However, Hoary Tansyaster grows to 3 feet, most of its leaves are linear or lanceolate and not fern-like and it has more ray flowers that are close enough together to touch each other. In Southwest Desert Flora also see Mesa Tansyaster, Machaeranthera tagetina.
Several ethno-botanical uses have been identified that include a decoction of the plant taken for stomachache and dried roots were used as snuff to cause sneezing to relieve congested nose. See the complete species account from Native American Ethnobotany, University of Michigan, Dearborn.