Petalonyx thurberi subsp. thurberi
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Family: Loasaceae · Type: Shrub · Native
Petalonyx thurberi subsp. thurberi is a native California shrub in the Loasaceae family.
Thurber's sandpaper plant is a California native shrub found in the southeastern desert region in sandy or gravelly dunes, washes, and creosote-bush scrub at elevations below 1,200 meters. Flowering from May to July, this plant produces small white to cream-colored flowers with stamens 6 to 10 millimeters long. Growing with rough, downward-pointing hairs, it forms a compact shrub with a distinctive texture. Its leaves are adapted to arid conditions, likely small and compact to minimize water loss in desert environments. The plant's rough, appressed hairs provide a unique textural quality that helps it survive in harsh desert landscapes.
Identification and appearance
Key characters: 4 sympatric species; key differentiators are hair type, leaf shape, and stamen length
Habitat and range
Habitat: Sandy or gravelly dunes, washes, canyons, creosote-bush scrub
Elevation: < 1200 m
California counties: San Bernardino, Riverside, Inyo, Los Angeles, Kern, San Diego, Imperial
Bloom period
Petalonyx thurberi subsp. thurberi blooms May-Jul.
How to tell it apart
vs Ambrosia: Petalonyx has showy white 5-petaled flowers; Ambrosia has tiny greenish flowers in heads.; vs Atriplex: Petalonyx has 5-petaled flowers; Atriplex has no petals, only sepals.; vs Eriastrum: Petalonyx has 5 stamens and woody stems; Eriastrum has many stamens and herbaceous stems.; vs Galium: Petalonyx has 5-petaled flowers; Galium has 4-petaled flowers in whorls.; vs Eucnide: Petalonyx is a woody shrub; Eucnide is an annual herb.
Frequently asked questions
Is Petalonyx thurberi subsp. thurberi native to California?
Yes. Petalonyx thurberi subsp. thurberi is native to California (recorded as native).
When does Petalonyx thurberi subsp. thurberi bloom?
Petalonyx thurberi subsp. thurberi blooms May-Jul.
Where in California does Petalonyx thurberi subsp. thurberi grow?
Petalonyx thurberi subsp. thurberi occurs in San Bernardino, Riverside, Inyo, Los Angeles, Kern, San Diego, Imperial, at elevations of < 1200 m.
What plant family does Petalonyx thurberi subsp. thurberi belong to?
Petalonyx thurberi subsp. thurberi is in the Loasaceae family, genus Petalonyx.
What habitat does Petalonyx thurberi subsp. thurberi grow in?
Petalonyx thurberi subsp. thurberi grows in Sandy or gravelly dunes, washes, canyons, creosote-bush scrub.
Related species
Other California species in the same genus, family, or bioregion.
- Petalonyx linearis — Long leaved sandpaper plant
- Petalonyx nitidus — Shiny leaf sandpaper plant
- Petalonyx sp. — Sandpaper-plant
- Petalonyx thurberi — Sandpaper plant
- Petalonyx thurberi subsp. gilmanii — Death valley sandpaper-plant
- Eucnide rupestris — Annual rock-nettle
- Eucnide sp. — Rock-nettle
- Eucnide urens — Desert bush nettle
- Loasaceae sp. — Loasa family
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.