''Machaeranthera'' is a genus of

North American North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Ca ...

flowering plants in the family

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...

which are known by the common name tansyaster.Flora of North America Vol. 20 Page 394 ''Machaeranthera'' Nees, Gen. Sp. Aster. 13, 224. 1832.
/ref> Tansyasters are variable in appearance. Some are small, singular wildflowers, while others are sprawling shrubs. Several species easily hybridize with each other, as well, making identification difficult. In general, members of the genus may be identified by the sharp-pointed, dagger-shaped

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

in the disc florets at the center of the flower. The flower heads are usually daisylike, and are usually a shade of purple or blue, but may be pink, yellow, or white. Tansyasters are native to western North America. The genus ''Machaeranthera'' is distinguished from the genus '' Dieteria'' by having once- or twice-pinnate leaves, whereas ''Dieteria'' has entire to toothed leaves.Mojave Desert Wildflowers, Pam MacKay, 2nd Ed. 2013, p. 39 ''Machaeranthera'' means "swordlike

".Great Basin Wildflowers, Laird R. Blackwell, 2006, p. 26 ; SpeciesBiota of North America Program 2013 county distribution maps
/ref>

References

External links

Jepson Manual Treatment

USDA Plants Profile
{{Taxonbar, from=Q547333 Astereae Asteraceae genera