Thalictrum occidentale

Summary

Thalictrum occidentale is a species of flowering plant in the buttercup family known by the common name western meadow-rue.[2] It is native to northwestern North America from Alaska and western Canada to northern California to Wyoming and Colorado, where it grows in shady habitat types such as forest understory and more open, moist habitat such as meadows.

Thalictrum occidentale
Female flowers (shown) have 1.5 to 2 mm long sepals, no petals, and up to 15 purple stigmas, 3 to 4.5 mm long including the style.[1]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Ranunculales
Family: Ranunculaceae
Genus: Thalictrum
Species:
T. occidentale
Binomial name
Thalictrum occidentale
Male flowers (shown) have four, sometimes six, light green to purplish, obovate 3.5 to 4.5 mm long sepals, no petals, and 15 to 30 disordered hanging stamens with purple-brown threadlike filaments, 4 to 10 mm long. The anthers are sharp-tipped, 1.5 to 4 mm long.[1]

Thalictrum occidentale is a perennial herb growing erect to a maximum height around a meter. It is hairless to lightly hairy and glandular. The leaves have compound blades divided into a few or many segments, often with three lobes, and are borne on long, slender petioles. The inflorescence is an upright or arching panicle of flowers with leaflike, lobed bracts often growing at the base. The species is dioecious, with male and female flowers occurring on separate plants, and is wind pollinated.[3] The male flower has a bell-shaped calyx of four sepals in shades of greenish white or purple. From the calyx dangle many long, purple stamens tipped with large anthers. The female flower has a cluster of immature fruits tipped with styles in shades of purple. A cluster has 4 to 9, at times up to 14, fruits.

References edit

  1. ^ a b Klinkenberg, Brian., ed. (2013). "Thalictrum occidentale". E-Flora BC: Electronic Atlas of the Plants of British Columbia [eflora.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. Retrieved 1 April 2013.
  2. ^ USDA, NRCS (n.d.). "Thalictrum occidentale". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 9 December 2015.
  3. ^ Culley, Theresa M.; Weller, Stephen G.; Sakai, Ann K. (August 2002). "The evolution of wind pollination in angiosperms". Trends in Ecology & Evolution. 17 (8): 362. doi:10.1016/S0169-5347(02)02540-5.

External links edit

  •   Media related to Thalictrum occidentale at Wikimedia Commons
  • Jepson Manual Treatment of Thalictrum occidentale
  • Flora of North America
  • Washington Burke Museum
  • Thalictrum occidentale — UC Photo gallery