North America Native Plant

Robust Suncup

Botanical name: Camissonia robusta

USDA symbol: CARO13

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Robust Suncup: A Charming California Native for Your Wildflower Garden If you’re looking to add a splash of sunny yellow to your California native plant garden, the robust suncup (Camissonia robusta) might just be the perfect addition. This delightful little annual brings cheerful four-petaled flowers and authentic California charm to ...

Rare plant alert!

Region: Conservation status by state

Status: S3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ 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 ⚘

Robust Suncup: A Charming California Native for Your Wildflower Garden

If you’re looking to add a splash of sunny yellow to your California native plant garden, the robust suncup (Camissonia robusta) might just be the perfect addition. This delightful little annual brings cheerful four-petaled flowers and authentic California charm to naturalized landscapes and wildflower gardens.

What Makes Robust Suncup Special

Robust suncup is a true California native, found exclusively within the Golden State. As an annual forb—essentially a soft-stemmed herbaceous plant—it completes its entire life cycle in one growing season, making it a dynamic addition to gardens that change with the seasons.

This species is currently listed with a Global Conservation Status of S3?, which means its conservation status is somewhat undefined. While this doesn’t necessarily mean it’s endangered, it does suggest that gardeners should source seeds or plants responsibly from reputable native plant suppliers rather than collecting from wild populations.

Where Robust Suncup Grows

You’ll find robust suncup naturally occurring throughout California, where it has adapted to the state’s Mediterranean climate and diverse growing conditions. This native distribution makes it an excellent choice for gardeners seeking to create authentic California ecosystems in their landscapes.

Garden Appeal and Design Uses

Don’t let the robust name fool you—this is actually a charming, low-growing plant that produces small but abundant yellow flowers in spring. The four-petaled blooms create a carpet of color that’s perfect for:

  • Native wildflower meadows and prairies
  • Naturalized garden areas
  • Ground cover in appropriate climates
  • Pollinator gardens focused on native species

As an annual, robust suncup adds seasonal interest and allows for changing garden compositions from year to year.

Pollinator and Wildlife Benefits

Like many members of the evening primrose family, robust suncup attracts various native pollinators, particularly small native bees. By including this species in your garden, you’re supporting local pollinator populations and contributing to biodiversity conservation.

Growing Conditions and Climate Zones

Robust suncup thrives in USDA hardiness zones 8-10, making it suitable for most of California’s growing regions. This sun-loving plant performs best when given:

  • Full sun exposure
  • Well-draining soil
  • Minimal water once established
  • Space to naturalize and self-seed

As a California native, it’s adapted to the state’s natural rainfall patterns and typically doesn’t require supplemental irrigation once established.

Planting and Care Tips

Growing robust suncup successfully is relatively straightforward if you follow these guidelines:

  • Timing: Direct seed in fall to align with natural rainfall patterns
  • Soil preparation: Ensure excellent drainage—this plant doesn’t tolerate soggy conditions
  • Watering: Water gently until germination, then reduce frequency as plants establish
  • Maintenance: Allow plants to complete their lifecycle and drop seeds for next year’s display

One of the joys of growing annual wildflowers like robust suncup is their ability to self-seed, creating evolving displays that change subtly from year to year.

Should You Plant Robust Suncup?

If you’re gardening in California and want to support native biodiversity while enjoying cheerful spring blooms, robust suncup is definitely worth considering. Just remember to source your seeds or plants from reputable native plant nurseries or seed companies that practice ethical collection methods.

This species is particularly well-suited for gardeners who enjoy naturalized landscapes and don’t mind the seasonal nature of annual plants. It’s an excellent choice for those creating habitat gardens or anyone interested in preserving California’s native plant heritage.

While robust suncup may not be the showiest plant in your garden, its authentic California origins and pollinator benefits make it a valuable addition to native plant collections. Plus, there’s something deeply satisfying about growing plants that have called your region home for thousands of years!

Robust 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 robusta P.H. Raven - robust suncup

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