North America Native Plant

Cooper’s Popcornflower

Botanical name: Plagiobothrys collinus var. ursinus

USDA symbol: PLCOU

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Echidiocarya californica A. Gray var. ursina (A. Gray) Jeps. (ECCAU)  âš˜  Plagiobothrys californicus (A. Gray) Greene var. ursinus (A. Gray) I.M. Johnst. (PLCAU)   

Cooper’s Popcornflower: A Charming California Native for Wildflower Gardens Meet Cooper’s popcornflower (Plagiobothrys collinus var. ursinus), a delightful little annual that brings a sprinkle of white blooms to California’s native plant palette. While it may not be the showiest flower in the garden, this humble native has its own quiet ...

Rare plant alert!

Region: Conservation status by state

Status: S5T2T4: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ Subspecies or varieties is apparently secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the region or more than 10,000 individuals ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Cooper’s Popcornflower: A Charming California Native for Wildflower Gardens

Meet Cooper’s popcornflower (Plagiobothrys collinus var. ursinus), a delightful little annual that brings a sprinkle of white blooms to California’s native plant palette. While it may not be the showiest flower in the garden, this humble native has its own quiet charm and plays an important role in supporting local ecosystems.

What Makes Cooper’s Popcornflower Special

This California endemic is a true forb – essentially a non-woody flowering plant that completes its entire life cycle in a single year. Cooper’s popcornflower produces clusters of small, white flowers with cheerful yellow centers that bloom primarily in spring. The plant stays relatively low to the ground, making it perfect for filling in gaps in naturalized plantings.

As a native species found exclusively in California, Cooper’s popcornflower has evolved alongside local wildlife and pollinators. It’s particularly attractive to small native bees and other beneficial insects during its blooming period.

Where Cooper’s Popcornflower Grows

This plant is endemic to California, where it grows in various habitats from coastal areas to inland regions. Its natural range reflects its adaptation to the state’s Mediterranean climate patterns.

Important Conservation Considerations

Before adding Cooper’s popcornflower to your garden, it’s important to know that this variety has a conservation status that indicates some level of rarity or conservation concern. If you’re interested in growing this plant, make sure to source seeds or plants only from reputable native plant nurseries that collect responsibly and legally. Never collect from wild populations.

Growing Cooper’s Popcornflower Successfully

The good news is that Cooper’s popcornflower is relatively easy to grow if you can provide the right conditions:

  • Climate zones: Best suited for USDA zones 8-10, particularly areas with Mediterranean-type climates
  • Sunlight: Prefers full sun but can tolerate partial shade
  • Soil: Thrives in well-draining soils; avoid areas that stay waterlogged
  • Water: Minimal water needs once established; adapted to California’s dry summers

Planting and Care Tips

Since Cooper’s popcornflower is an annual, it’s typically grown from seed rather than transplants:

  • Direct seed in fall to allow for natural winter stratification
  • Scatter seeds lightly and barely cover with soil
  • Water gently until germination occurs
  • Once established, reduce watering significantly
  • Allow plants to set seed for natural reseeding

Perfect Garden Companions

Cooper’s popcornflower works beautifully in:

  • Native plant gardens featuring other California wildflowers
  • Naturalized meadow areas
  • Restoration projects
  • Rock gardens with good drainage
  • Areas where you want low-maintenance ground cover

Should You Grow Cooper’s Popcornflower?

If you’re passionate about California native plants and have the right growing conditions, Cooper’s popcornflower can be a lovely addition to your garden. Its modest blooms contribute to the overall tapestry of a native plant community, and it provides food for small pollinators during its blooming period.

However, given its conservation status, this might not be the best choice for beginning native plant gardeners. Consider starting with more common California natives like California poppies or lupines, and work up to rarer species as you gain experience and establish connections with reputable native plant sources.

Whether you choose to grow Cooper’s popcornflower or not, appreciating these small native treasures helps us understand the incredible diversity that makes California’s flora so special.

Cooper’s Popcornflower

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Lamiales

Family

Boraginaceae Juss. - Borage family

Genus

Plagiobothrys Fisch. & C.A. Mey. - popcornflower

Species

Plagiobothrys collinus (Phil.) I.M. Johnst. - Cooper's popcornflower

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA