Pediocactus nigrispinus

Pediocactus nigrispinus is a species in the cactus family with the common names snowball cactus, Columbia Plateau cactus, and basalt cactus. It is found in dry areas in Washington, Oregon, and Idaho.

Description
Pediocactus nigrispinus exhibits a diverse color range, varying from green to grayish-blue in its single stem but often as a cluster of stems. Initially spherical, the plant transforms into an egg-shaped configuration as it matures, densely spiny plant that forms an (often flattened) ovoid, reaching heights between 5 and 30 cm and diameters spanning 5 to 15 cm. Notably, this cactus is characterized by a dense arrangement of 6 to 12 central spines, measuring 15 to 35 mm in length and showcasing colors that range from brown to reddish, nearly black. These spines are robust and may either stand upright or possess a slight curve. The showy pink to magenta colored flowers appear in the spring and form a cluster near the apex of each stem. Full technical description at Flora of North America.

Range and habitat
The Columbia Plateau cactus grows in big sagebrush and lower montane dry habitats in eastern Washington and Oregon and extending into Idaho in dry regions, steppes and semi-deserts on hills or rocky outcrops at altitudes between 260 and 1200 meters. . It grows in scattered locations but is often locally abundant. Other plants in the habitat include Opuntia polyacantha and Opuntia fragilis.