Flora of the Columbia Plateau and Blue Mountains in Washington

Our understanding of plant diversity in the interior of Washington State is less complete than we would like. In order to better document and identify the species diversity for this region we are creating identification resources and checklists for the area. We are particularly focused on the Columbia Plateau and Blue Mountains eco-regions for the state of Washington, which encompass the entirety of Adams, Asotin, Benton, Columbia, Douglas, Franklin, Garfield, Grant, Lincoln, Walla Walla, and Whitman Counties, as well as the adjacent counties with portions of the Columbia Plateau including Chelan, Kittitas, Klickitat, Spokane, and Yakima Counties.

These materials have been compiled and created by Eric Roalson and Walter Fertig, unless otherwise noted. Feedback on these floristic treatments are welcome and can be provide to either of us – our contact information is available on the “Contact Us” page!

References

Several published references have been used in combination with herbarium records for this guide, particularly the Flora of the Pacific Northwest (Second Edition), Flora of North America, and Flora of Oregon.

Key to Major Groups

Plants reproducing by spores, spore bearing bodies typically on leafy vegetation or sometimes submerged underwater, not cone-bearing or flower-bearing. See Ferns and Lycophytes.
- Plants not reproducing by spores, cones or flowers present. … 2.
Plant reproductive structures in cones with separate male and female cones, growing as woody trees or shrubs. See Gymnosperms.
- Plant reproductive structures not in cones, flowers present although sometimes reduced and cryptic, woody and herbaceous growth forms. … 3.
Flowers with parts in 3s or multiples, or inconspicuous flowers in scale and bract structures (grasses, sedges, etc.), leaves typically with parallel venation. See Monocots.
- Flowers with parts in 4s, 5s, or more, leaves typically with reticulate or divergent-branching venation. See Dicots.