North America Native Plant

Cottonwood Springs Suncup

Botanical name: Camissonia exilis

USDA symbol: CAEX10

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Oenothera exilis P.H. Raven (OEEX)   

Cottonwood Springs Suncup: A Rare Desert Gem Worth Protecting If you’re passionate about desert gardening and conservation, you might be intrigued by the Cottonwood Springs suncup (Camissonia exilis). This petite annual wildflower represents one of nature’s more exclusive offerings – but that exclusivity comes with some serious responsibility. What Makes ...

Rare plant alert!

Region: Conservation status by state

Status: S2: Status is uncertain but is somewhere between the following rankings: 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) ⚘

Cottonwood Springs Suncup: A Rare Desert Gem Worth Protecting

If you’re passionate about desert gardening and conservation, you might be intrigued by the Cottonwood Springs suncup (Camissonia exilis). This petite annual wildflower represents one of nature’s more exclusive offerings – but that exclusivity comes with some serious responsibility.

What Makes This Plant Special

The Cottonwood Springs suncup is a delicate annual forb native to the American Southwest. Don’t let its humble appearance fool you – this little plant packs a punch with bright yellow, four-petaled flowers that create cheerful splashes of color in the harsh desert landscape. As an herbaceous plant without woody tissue, it completes its entire life cycle in a single growing season, making every bloom precious.

You might also encounter this plant listed under its scientific synonym, Oenothera exilis, but Camissonia exilis is the accepted name today.

Where You’ll Find It (If You’re Lucky)

This native beauty calls Arizona and Utah home, thriving in the unique conditions of the southwestern United States. Its distribution is extremely limited, which brings us to an important point about this plant’s status.

A Conservation Alert: Handle with Care

Here’s where things get serious, fellow gardeners. The Cottonwood Springs suncup carries a Global Conservation Status of S2, meaning it’s imperiled in the wild. With only an estimated 6 to 20 known occurrences and roughly 1,000 to 3,000 individual plants remaining, this species teeters on the edge of a conservation cliff.

What this means for gardeners: If you’re considering adding this plant to your collection, proceed with extreme caution and responsibility. Only source seeds or plants from verified conservation programs or botanical institutions – never collect from wild populations.

Growing Cottonwood Springs Suncup Responsibly

Should you obtain responsibly sourced material, here’s what this desert dweller needs to thrive:

  • Sunlight: Full sun exposure – this desert native loves intense light
  • Soil: Well-draining sandy or rocky soil that mimics its natural habitat
  • Water: Minimal irrigation once established; overwatering is more dangerous than drought
  • Climate: Best suited for USDA zones 8-10, matching its native range
  • Planting: Direct seed in fall for spring germination, following natural cycles

Garden Role and Design Ideas

If you’re fortunate enough to grow this rare gem, it works beautifully in:

  • Specialized desert or xeric gardens
  • Rock gardens with other southwestern natives
  • Conservation collections focused on rare species
  • Educational displays about plant conservation

Its small stature and delicate flowers make it perfect for close-up viewing areas where visitors can appreciate its subtle beauty.

Supporting Pollinators

Despite its rarity, the Cottonwood Springs suncup plays an important role in supporting native desert pollinators, including specialized bees and other small insects that have co-evolved with southwestern flora. Every flower counts when populations are this small!

The Bottom Line

While the Cottonwood Springs suncup is undeniably fascinating and beautiful, its imperiled status means it’s not your typical garden center purchase. If conservation gardening is your passion and you can source seeds ethically, this plant offers a unique opportunity to participate in species preservation right in your backyard.

For most gardeners interested in supporting desert ecosystems, consider more common native alternatives like desert marigold, brittlebush, or other Oenothera species that provide similar benefits without the conservation concerns.

Remember: the best way to help rare plants like the Cottonwood Springs suncup is to support their natural habitats and conservation efforts. Sometimes the most loving thing we can do is admire from a distance and work to protect what remains in the wild.

Cottonwood Springs Suncup

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Myrtales

Family

Onagraceae Juss. - Evening Primrose family

Genus

Camissonia Link - suncup

Species

Camissonia exilis (P.H. Raven) P.H. Raven - Cottonwood Springs suncup

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