Mammillaria dioica
Fish hook cactus
Photo by Chez Brungraber
Family: Cactaceae · Type: Shrub · Native
Mammillaria dioica (Fish hook cactus) is a native California shrub in the Cactaceae family.
Fish hook cactus is a California native perennial found in southern coastal and western edge of the desert regions in hillsides, washes, and coastal scrub at elevations of 10 to 1,500 meters. Flowering from February to April, this cactus produces white to pinkish flowers 10 to 22 millimeters long with inner perianth parts numbering 8 to 12. Growing 5 to 30 centimeters tall with a spheric to long-cylindric form, it develops firm stems with bristly tubercle axils. Its distinctive spines include 1 to 4 central spines per areole, with one spine notably hooked, and 11 to 22 radial spines surrounding the main central spine. The fruit matures to an ovoid or club-shaped structure 10 to 25 millimeters long, characteristic of this desert-dwelling cactus.
Identification and appearance
Key characters: 0 sympatric species - geographically isolated in SCo region
Habitat and range
Habitat: Hillsides, washes, coastal scrub to creosote-bush scrub
Elevation: 10-1500 m
California counties: San Diego, Riverside, San Bernardino, Imperial
Outside California: Baja California
Bloom period
Mammillaria dioica blooms Feb-Apr.
How to tell it apart
vs Cochemiea: Mammillaria has hooked central spines; Cochemiea has straight central spines (formerly split from Mammillaria).; vs Escobaria: Mammillaria has tubercles without grooves; Escobaria has grooved tubercles running from spine to base.; vs Ferocactus: Mammillaria has tubercles not ribs; Ferocactus has prominent vertical ribs.; vs Kroenleinia: Mammillaria has distinct hooked spines; Kroenleinia has straight or slightly curved spines.; vs Echinocereus: Mammillaria has single or few-stemmed clusters with tubercles; Echinocereus forms large soft clusters with ribs.
Frequently asked questions
Is Mammillaria dioica native to California?
Yes. Mammillaria dioica is native to California (recorded as native).
When does Mammillaria dioica bloom?
Mammillaria dioica blooms Feb-Apr.
Where in California does Mammillaria dioica grow?
Mammillaria dioica occurs in San Diego, Riverside, San Bernardino, Imperial, at elevations of 10-1500 m.
What plant family does Mammillaria dioica belong to?
Mammillaria dioica is in the Cactaceae family, genus Mammillaria.
What habitat does Mammillaria dioica grow in?
Mammillaria dioica grows in Hillsides, washes, coastal scrub to creosote-bush scrub.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.