Machaeranthera tanacetifolia

(Kunth) Nees

Gen. Sp. Aster., 225. 1832.

Common names: Tansy-aster tansyleaf aster tahoka-daisy
Illustrated
Basionym: Aster tanacetifolius Kunth in A. von Humboldt et al., Nov. Gen. Sp. 4(fol.): 74. 1818; 4(qto.): 95. 1820
Treatment appears in FNA Volume 20. Treatment on page 394. Mentioned on page 395.

Annuals or biennials, 5–100 cm. Leaves 8–110 × 4–40 mm. Involucres hemispheric, 6–11 mm. Phyllaries (24–)40–80(–100) in 3–6 series, linear-lanceolate to linear, 4–11 × 0.5–1.2 mm, apices usually spreading to reflexed, sometimes appressed, long-acuminate. Receptacles flat to convex, 3.5–8(–10) mm diam. Ray florets 12–40(–50); laminae 8–20 × 1–3.5 mm. Disc florets (18–)40–160; corollas 4–7 mm, glabrous or glabrate; lobes 0.3–0.7(–1) mm, glabrous. Cypselae 2–3.5(–4) mm; pappi 2–8 mm. 2n = 8.


Phenology: Flowering Mar–Oct.
Habitat: Grasslands, Larrea-dominated desert scrub, pine-oak and pinyon-juniper woodlands, streambeds, roadsides, disturbed areas
Elevation: 800–2500 m

Distribution

V20-898-distribution-map.gif

Alta., Ariz., Calif., Colo., Kans., Mont., Nebr., Nev., N.Mex., Okla., S.Dak., Tex., Utah, Wyo., Mexico (Aguascalientes, Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Zacatecas).

Discussion

Machaeranthera tanacetifolia is present in the southern Rocky Mountains, western Great Plains, and southwestern desert regions. It has also been reported from Illinois and New York, but in both cases is most likely introduced. Because of its large showy heads, M. tanacetifolia is sometimes planted as an ornamental.

Selected References

None.

Lower Taxa

None.
David R. Morgan +  and Ronald L. Hartman +
(Kunth) Nees +
Aster tanacetifolius +
Tansy-aster +, tansyleaf aster +  and tahoka-daisy +
Alta. +, Ariz. +, Calif. +, Colo. +, Kans. +, Mont. +, Nebr. +, Nev. +, N.Mex. +, Okla. +, S.Dak. +, Tex. +, Utah +, Wyo. +, Mexico (Aguascalientes +, Chihuahua +, Coahuila +, Durango +, Nuevo León +, San Luis Potosí +  and Zacatecas). +
800–2500 m +
Grasslands, Larrea-dominated desert scrub, pine-oak and pinyon-juniper woodlands, streambeds, roadsides, disturbed areas +
Flowering Mar–Oct. +
Gen. Sp. Aster., +
Illustrated +
Compositae +
Machaeranthera tanacetifolia +
Machaeranthera +
species +