North America Native Plant

Atwood’s Evening Primrose

Botanical name: Camissonia atwoodii

USDA symbol: CAAT10

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Atwood’s Evening Primrose: A Rare Utah Gem That Needs Our Protection Meet Atwood’s evening primrose (Camissonia atwoodii), one of Utah’s most precious and endangered wildflowers. This little annual is so rare that you’re more likely to spot a shooting star than find one growing in the wild. But before you ...

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) ⚘

Atwood’s Evening Primrose: A Rare Utah Gem That Needs Our Protection

Meet Atwood’s evening primrose (Camissonia atwoodii), one of Utah’s most precious and endangered wildflowers. This little annual is so rare that you’re more likely to spot a shooting star than find one growing in the wild. But before you start planning to add this botanical unicorn to your garden, there are some important things you need to know.

A True Utah Native

Atwood’s evening primrose is a proud Utah native, found nowhere else in the world. This makes it what botanists call an endemic species – it’s as uniquely Utahn as fry sauce and the Great Salt Lake. As an annual forb (that’s fancy talk for a non-woody herbaceous plant), it completes its entire life cycle in just one growing season.

Currently, this rare beauty is only known to exist in Utah, making it one of the state’s most geographically restricted plants.

Why This Plant is Special (And Why You Probably Shouldn’t Grow It)

Here’s where things get serious. Atwood’s evening primrose has a Global Conservation Status of S2, which means it’s imperiled. In plain English? This plant is hanging on by a thread. Scientists estimate there are only 6 to 20 known populations left, with somewhere between 1,000 to 3,000 individual plants remaining in the wild.

This rarity status means that Atwood’s evening primrose isn’t your typical garden center find – and frankly, it shouldn’t be. Here’s why responsible gardeners should think twice:

  • Removing plants or seeds from wild populations could push this species closer to extinction
  • The specific growing conditions it needs are likely very specialized and difficult to replicate
  • Conservation efforts should focus on protecting existing wild populations first

What We Know About Growing Conditions

Unfortunately, detailed information about Atwood’s evening primrose’s specific growing requirements is limited – which is often the case with rare, specialized plants. What we can infer from its Utah habitat and evening primrose family connections:

  • Likely prefers arid or semi-arid conditions typical of Utah’s climate
  • Probably needs specific soil types found in its native range
  • As an annual, it would complete its growth cycle in one season
  • May require specific temperature and moisture patterns to germinate and thrive

Better Alternatives for Your Garden

Instead of seeking out this rare species, consider these more common evening primroses and related natives that can give you similar beauty without conservation concerns:

  • Common evening primrose (Oenothera biennis) – widely available and pollinator-friendly
  • Pink evening primrose (Oenothera speciosa) – drought-tolerant with lovely pink blooms
  • Other Utah native wildflowers that are more common and suitable for cultivation

Supporting Conservation Instead

If you’re drawn to Atwood’s evening primrose because of its rarity and Utah heritage, consider supporting conservation efforts instead:

  • Donate to botanical conservation organizations working in Utah
  • Support habitat protection initiatives
  • Choose other native Utah plants that aren’t imperiled
  • Spread awareness about rare plant conservation

The Bottom Line

Atwood’s evening primrose is undoubtedly a fascinating and important part of Utah’s natural heritage. However, its critically imperiled status means it belongs in conservation programs and protected habitats, not home gardens. Sometimes the most loving thing we can do for a plant is admire it from afar and work to protect the wild spaces where it can continue to survive and hopefully thrive.

By choosing more common native alternatives, you can still create beautiful, ecologically valuable gardens while leaving rare species like Atwood’s evening primrose to the conservation professionals who are working hard to ensure future generations can appreciate these botanical treasures.

Atwood’s Evening Primrose

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 atwoodii Cronquist - Atwood's evening primrose

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