Machaeranthera

tansyasters
Machaeranthera asteroides
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Asterales
Family: Asteraceae
Genus: Machaeranthera
Nees
Type species
Aster tanacetifolius[1]
Kunth.
Synonyms[2]
  • Hesperastrum A.Gray
  • Aster sect. Machaeranthera (Nees) Benth. & Hook. f.
  • Aster subgen. Machaeranthera (Nees) A. Gray

Machaeranthera is a genus of North American flowering plants in the daisy family which are known by the common name tansyaster.[3][4]

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 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.[4]

The genus Machaeranthera is distinguished from the genus Dieteria by having once or twice pinnate leaves, whereas Dieteria has entire to toothed leaves.[5]

"Machaeranthera" means "swordlike anthers".[6]

Species[2][7]
  1. Machaeranthera arenaria - Baja California Sur
  2. Machaeranthera carnosa - shrubby alkali aster - New Mexico, Arizona, California, Nevada, Sonora
  3. Machaeranthera coulteri - California, Sonora
  4. Machaeranthera crispa - Baja California Sur
  5. Machaeranthera crutchfieldii - Nuevo León
  6. Machaeranthera gracilis - slender goldenweed - California, Nevada, Utah, Colorado, Arizona, Nevada, Texas, Chihuahua
  7. Machaeranthera grindelioides - rayless tansyaster - from Arizona to Alberta
  8. Machaeranthera gypsophila - gypsum tansyaster - Coahuila
  9. Machaeranthera gypsitherma - New Mexico
  10. Machaeranthera heterophylla - Nuevo León
  11. Machaeranthera incisifolia - northern Baja California
  12. Machaeranthera johnstonii - Coahuila
  13. Machaeranthera juncea - rush bristleweed - California
  14. Machaeranthera pinnatifida - lacy tansyaster - Saskatchewan
  15. Machaeranthera restiformis - Coahuila
  16. Machaeranthera setigera - Mexico
  17. Machaeranthera stenoloba - Chihuahua
  18. Machaeranthera tagetina - mesa tansyaster - Sonora, Arizona, New Mexico
  19. Machaeranthera tanacetifolia - tansyleaf tansyaster - from Alberta to Zacatecas
  20. Machaeranthera tenuis - Nuevo León, Texas
  21. Machaeranthera turneri - Chihuahua
  22. Machaeranthera viscida - sticky tansyaster - Texas, New Mexico
  23. Machaeranthera wigginsii - northern Baja California

References

  1. Tropicos, Machaeranthera Nees
  2. 2.0 2.1 Flann, C (ed) 2009+ Global Compositae Checklist
  3. Nees von Esenbeck, Christian Gottfried Daniel. 1832. Genera et Species Asterearum 13, 224–225
  4. 4.0 4.1 Flora of North America Vol. 20 Page 394 Machaeranthera Nees, Gen. Sp. Aster. 13, 224. 1832.
  5. Mojave Desert Wildflowers, Pam MacKay, 2nd Ed. 2013, p. 39
  6. Great Basin Wildflowers, Laird R. Blackwell, 2006, p. 26
  7. Biota of North America Program 2013 county distribution maps

External links