Tansyleaf Aster
Machaeranthera tanacetifolia (Humboldt, Bonpland, & Kunth) Nees MATA2
Distribution and Habitat: Tansyleaf Aster is found in mixed desert shrub, salt desert shrub, and pinyon juniper communities at elevations from 2,750’-5,950’ in Beaver, Carbon, Emery, Garfield, Grand, Iron, Juab, Kane, Salt Lake, San Juan, Sevier, Utah, Wasatch, Washington, and Wayne counties. General Information: Tansyleaf Aster is somewhat weedy. It readily moves into disturbed sandy and silty soils. It is commonly found in vacant lots. Asters and Fleabanes are often mistaken for one another. They are easily distinguished by the bracts. Aster bracts are in several ranks and often bent outwards. Fleabane’s have only 1 or 2 ranks of bracts which are nearly equal in length and don’t bend outwards as markedly as an Aster.
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ASTERACEAE
Description: Tansyleaf Aster is a native, tap rooted annual to biennial plant in the Sunflower Family (Asteraceae). Stems are 3”-20” tall, often marked with usually parallel lines or grooves tinged with purple. Stems are simple or branched, forming rounded clumps, and are glandular-fine hairy to shaggy-hairy. Leaves are ⅜”-2⅓” long, once or twice deeply lobed with the segments ending in spiny bristles. It flowers from July to October producing 1 to many flower heads in flat-topped or round-topped clusters. Whorls of bracts below individual flower heads are shaped like half spheres. Bracts are linear and lance-shaped with pointed tips, papery at the base, green at the spreading, bent backward tips. Flower heads have 11-23 pink-purple, blue-purple, or violet ray flowers about ½” long. Tansyleaf Aster produces achenes with soft, straight hairs that are approximately 1/10” inch long.