The Pediocactus nigrispinus, commonly known as the Columbia Plateau cactus, snowball cactus, basalt cactus, or hedgehog cactus, grows in lowland and montane sagebrush deserts throughout Eastern Oregon, West-central Idaho, and Central and Eastern Washington.  Specifically, the Columbia Plateau cactus is found in the Washington counties of Chelan, Kittitas, Yakima, Douglas, and Grant.  The Columbia Plateau cactus flowers from April to July and typically produces pink flowers.  However, it may also produce purple, white, peach, or yellow flowers.  The Columbia Plateau cactus reaches heights between 5 and 30 centimeters and diameters spanning 5 to 15 centimeters.  This cactus is characterized by a dense arrangement of 6 to 12 central spines measuring 15 to 35 millimeters in length and showcasing colors ranging from brown to reddish black.  The cactus receives its taxonomic name from its reddish black spines.

There are three other native cacti species in Washington:  the Opuntia columbiana, the Opuntia polyacantha, and the Opuntia fragilis, which is known as the brittle prickly pear.

Washington has an official state tree, the western hemlock (Tsuga heterophylla); an official state grass, bluebunch wheatgrass (Agropyron spicatum); and an official state flower, the coastal rhododendron (Rhododendron macrophyllum).

The Columbia Plateau cactus (Pediocactus nigrispinus) is designated as the official cactus of the State of Washington.