North America Native Plant

Clementine Suncup

Botanical name: Camissonia guadalupensis clementina

USDA symbol: CAGUC

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Oenothera guadalupensis S. Watson p.p. (OEGU2)  âš˜  Oenothera guadalupensis S. Watson ssp. clementina P.H. Raven (OEGUC)   

Clementine Suncup: A Rare California Native Worth Protecting in Your Garden Meet the Clementine suncup (Camissonia guadalupensis clementina), a charming little wildflower that’s as rare as it is beautiful. This delicate annual belongs to California’s native flora and represents one of those special plants that dedicated native gardeners dream of ...

Rare plant alert!

Region: Conservation status by state

Status: S3T3: Status is uncertain but is somewhere between the following rankings: Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ Subspecies or variety is vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals. ⚘

Clementine Suncup: A Rare California Native Worth Protecting in Your Garden

Meet the Clementine suncup (Camissonia guadalupensis clementina), a charming little wildflower that’s as rare as it is beautiful. This delicate annual belongs to California’s native flora and represents one of those special plants that dedicated native gardeners dream of growing successfully.

What Makes Clementine Suncup Special?

The Clementine suncup is a true California native, found naturally only within the Golden State’s borders. As an annual forb—that’s gardener-speak for a non-woody flowering plant—it completes its entire life cycle in just one growing season. Don’t let its modest stature fool you, though. This little beauty packs a punch with its cheerful yellow blooms that appear in spring.

You might also encounter this plant listed under its synonyms: Oenothera guadalupensis or Oenothera guadalupensis ssp. clementina. It’s all the same lovely plant, just with different names depending on which botanical reference you’re consulting.

Geographic Distribution and Rarity

The Clementine suncup calls California home exclusively, making it a true endemic species. This limited distribution contributes to its conservation status of S3T3, which indicates the plant faces some level of conservation concern.

Important Conservation Note

Here’s something crucial for responsible gardeners: because of its rarity status, you should only plant Clementine suncup if you can source it responsibly. This means purchasing seeds or plants from reputable native plant nurseries that propagate their stock rather than wild-collecting. Never harvest seeds or plants from wild populations—this can harm already vulnerable populations.

Garden Appeal and Landscape Role

So why might you want to grow this rare beauty? The Clementine suncup brings authentic California character to native plant gardens. Its delicate yellow flowers provide a subtle splash of color in spring, and as a true native, it supports local ecosystem health in ways that non-native plants simply cannot match.

This plant works beautifully in:

  • Native California wildflower meadows
  • Rock gardens with excellent drainage
  • Drought-tolerant landscapes
  • Conservation-focused botanical collections

Growing Conditions and Care

Like many California natives, the Clementine suncup appreciates conditions that mimic its natural habitat. Think Mediterranean climate with dry summers and mild, wet winters. It thrives in USDA hardiness zones 9-10, which corresponds to California’s coastal and inland valley regions.

Key growing requirements include:

  • Sunlight: Full sun exposure
  • Soil: Well-draining soil is essential—soggy conditions spell disaster
  • Water: Drought-tolerant once established, but benefits from winter moisture
  • Climate: Mediterranean-type climate with dry summers

Planting and Care Tips

Since this is an annual, you’ll need to start fresh each year, but that’s part of the charm! Direct seeding in fall typically works best, allowing the seeds to experience the natural winter chill they need for proper germination.

Here’s your care roadmap:

  • Sow seeds in fall when temperatures begin to cool
  • Provide minimal supplemental water—overwatering is more dangerous than underwatering
  • Allow plants to self-seed for potential natural regeneration
  • Avoid fertilizing, as natives often prefer lean soils

Wildlife and Pollinator Benefits

As a native California wildflower, the Clementine suncup likely attracts native bees and other pollinators, though specific wildlife relationships for this rare subspecies aren’t well-documented. What we do know is that native plants almost always provide better support for local wildlife than non-native alternatives.

Should You Grow Clementine Suncup?

If you’re a dedicated native plant enthusiast in California with access to responsibly sourced material, absolutely! Growing rare natives like the Clementine suncup helps maintain genetic diversity in cultivation and can contribute to conservation efforts. However, this isn’t a plant for casual gardeners—it requires specific conditions and responsible sourcing.

For gardeners outside California or those seeking easier alternatives, consider other native suncups or evening primroses native to your specific region. Every area has its own wonderful native wildflowers that deserve a place in our gardens.

Remember: gardening with rare natives is both a privilege and a responsibility. When done thoughtfully, it’s one of the most meaningful ways to connect with and protect our natural heritage.

Clementine 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 guadalupensis (S. Watson) P.H. Raven - Guadalupe suncup

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