Pediocactus simpsonii (Engelm.) Britton & Rose
Simpson Hedgehog Cactus, Mountain Ball Cactus
Cactaceae (Cactus Family)
USDA Symbol: PESI
Although pediocactus simpsonii has a wide geographic distribution, from Oregon and Montana south to Arizona and New Mexico, the cactus is still relatively uncommon, growing in high elevation locations, often in small, localized areas, frequently obscured by grass and fallen leaves. The plant may form clusters but usually remains solitary, starting as a neat globe, becoming elongated and cylindrical when aged (up to 10 inches tall).
The 15 to 35 white radial spines are thin and short, while the 4 to 11 central spines are thicker, longer (up to 3/4 inch), and brown or yellow at the tips; all grow from pronounced tubercles, arranged in spirals. Spine cover tends to be dense, nearly or completely obscuring the green stems, though in some specimens the spines are much shorter, and fewer in number.
The plants appearance changes greatly in different locations, and several sub species have been proposed, but distinguishing features are so variable across the 900 mile range that precise identification is difficult.
This cactus is fairly popular with collectors. Other species of the genus are rare. Mass collecting of cacti is inexcusable, but even the person who digs only one has a detrimental effect, for if many take only their share eventually entire plant populations are depleted.
Description provided courtesy of The American Southwest.
From the Image Gallery
Plant CharacteristicsDuration: Perennial
Size Notes: Up to 10 inches tall.
Flower: Yellow at the center, white to pink around the edges, up to 1 inch long.
Size Class: 0-1 ft.
Bloom InformationBloom Color: Pink , Yellow
Bloom Time: May , Jun , Jul , Aug
Bloom Notes: Diurnal.
DistributionUSA: AZ , CO , ID , MT , NM , NV , OR , SD , UT , WA , WY
Native Distribution: The Rocky Mountains, from south Montana to north New Mexico; also scattered locations in Oregon, Nevada, Utah and Arizona.
Native Habitat: Grassland, sagebrush flats, pinyon-juniper woodland; up to 11,000 feet elevation.
Growing ConditionsWater Use: Low
Light Requirement: Sun
Soil Moisture: Dry
Conditions Comments: Minimum temperature 45F.
Find Seed or Plants
Find seed sources for this species at the Native Seed Network.
From the National Organizations DirectoryAccording to the species list provided by Affiliate Organizations, this plant is on display at the following locations:
Native Seed Network - Corvallis, OR
BibliographyBibref 1140 - Cacti (1991) Clive Innes and Charles Glass
Search More Titles in Bibliography
Web ReferenceWebref 15 - The American Southwest (1994) John Crossley
Additional resourcesUSDA: Find Pediocactus simpsonii in USDA Plants
FNA: Find Pediocactus simpsonii in the Flora of North America (if available)
Google: Search Google for Pediocactus simpsonii
MetadataRecord Modified: 2018-08-30
Research By: TWC Staff