Flower profile
Whitestem paperflower
Psilostrophe cooperi
Whitestem paperflower (Psilostrophe cooperi) is a low shrub in the Asteraceae family, native in the lower 48 states, blooming mostly April–November across the U.S.
Whitestem paperflower is a wildflower that USDA PLANTS lists as native in the lower 48 states. In Nevada it's most often seen in bloom in April–November.
*iNaturalist research-grade observations, as of October 17, 2026.
On our lists for: Nevada
Quick look
Psilostrophe cooperi is a flowering plant in the daisy family known by the common names Cooper's paper daisy and whitestem paperflower. It is native to the Mojave and Sonoran Deserts of California, the Southwestern United States, and northwestern Mexico.
- It belongs to the Asteraceae family. iNaturalist
- USDA PLANTS describes it as an herb (forb) / a subshrub with a perennial life cycle. USDA PLANTS
- USDA PLANTS lists it as native in the lower 48 states and records it in 5 states. USDA PLANTS
- NatureServe lists it as native to Nevada. NatureServe
- In Nevada, most iNaturalist sightings of it in flower come in April–November. iNaturalist
- iNaturalist has 512 research-grade sightings of it in Nevada, ranking #81 among the 132 flowers on our Nevada list. iNaturalist
When does it bloom?
In Nevada, most flowering sightings come in April–November.
Conservation status
- Federal (U.S. ESA)
- Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
- NatureServe global
- G5 Secure worldwide. NatureServe
- Nevada
- Not listed Not on Nevada fully protected plants, critically endangered (NAC 527.010). NatureServe: S4, apparently secure in Nevada. NAC 527.010
- Rare elsewhere
- Other states where NatureServe ranks it rare or missing: UT (S2). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)
Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.
Can you eat it?
None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.
It isn't on the ASPCA plant list.
🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.
Where does it grow?
USDA PLANTS records whitestem paperflower in 5 states.
recorded by USDA PLANTS on our state lists not recorded
See the full list of states
Arizona, California, Nevada, New Mexico, Utah.
Nevada counties with USDA records: Clark, Lincoln, Nye.
Names, range and relatives
Other scientific names (synonyms in USDA PLANTS): Riddellia cooperi.
County records: USDA PLANTS lists it in 22 counties across 5 states; the most are in Arizona (12), California (3), Nevada (3).
More from the Asteraceae family (212 on Bloomipedia; most observed first): Common yarrow, Goldenrods, White snakeroot, Sunflowers, Chicory, Black-eyed Susan, Bull thistle, Common dandelion.
More Nevada flowers
Sources
- USDA, NRCS. PLANTS Database, profile PSCO2.
- iNaturalist, Psilostrophe cooperi: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
- Wikipedia, Psilostrophe cooperi (lead quoted under CC BY-SA 4.0).
- Nevada: Nevada fully protected plants, critically endangered (NAC 527.010).
- Nevada: Nevada noxious weeds (NAC 555.010).
- USFWS, ECOS species database (ESA listing check), October 17, 2026.
- NatureServe Explorer, Psilostrophe cooperi (global and state ranks).
- Edibility and toxicity: no source found (marked "not well documented").
- Photo: Bobby McCabe via iNaturalist · CC BY 4.0 · resized.