Dieteria canescens, Hoary Tansyaster
Scientific Name: Dieteria canescens
Common Name: Hoary Tansyaster
Also Called: Hoary Aster, Hoary Goldenweed, Hoary Machaeranthera, Hoary Tansy-aster, and Purple Aster
Family: Asteraceae, Sunflower Family
Synonyms: (Aster canescens Machaeranthera oxylepis, Machaeranthera canescens)
Duration: Annual, biennial or perennial.
Size: Up to 3 feet or more.
Growth Form: Forb/herb, subshrub; 1 or more stems from base, stems green, branching above, stems pubescent variable, glandular, hairy or hairless.
Leaves: Green; small, lower and upper leaves linear, lanceolate or oblanceolate, glabrous, puberulent or canescent .
Flower Color: Purple or bluish-purple; radiate numerous flower heads, ray flowers numerous, slender, disk flowers yellow; numerous, bracts or phyllaries below flower heads variable, spreading or reflexed; fruit is an achene.
Flowering Season: June to November.
Elevation: 150 to 8,000 feet.
Habitat Preferences: Various habitats across a wide geographic range, pine forests, chaparral and upper and lower deserts, usually dry areas, open areas, roadsides and disturbed areas.
Recorded Range: In the western half of the United States, western Canada and northern Mexico. In Arizona this species occurs in the northern and southern half of the state.
U.S. Weed Information: Dieteria canescens is listed in: Weeds of the West. Plants included here may become weedy or invasive.
Invasive/Noxious Weed Information: No data available.
Wetland Indicator: Dieteria canescens is on the USDA 2012 National Wetland Plant List.
Threatened/Endangered Information: No data available
Comments: Hoary Tansyaster is a common species that was recently re-classified from Machaeranthera to Dieteria. Hoary Tansyaster is highly variable across its range and similar in appearance to several Machaeranthera species but particularly similar in appearance to Tansyleaf Tansyaster, Machaeranthera tanacetifolia. In general, Hoary Tansyaster has leaves that are linear or lanceolate, not pinnatifid, and has more and narrower ray flowers that grow close together to touch each other.
Also see Mesa Tansyaster, Machaeranthera tagetina.