North America Native Plant

Roosevelt Dam Rockdaisy

Botanical name: Perityle saxicola

USDA symbol: PESA12

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Laphamia saxicola Eastw. (LASA5)   

Roosevelt Dam Rockdaisy: A Rare Arizona Treasure Worth Protecting Meet the Roosevelt Dam rockdaisy (Perityle saxicola), one of Arizona’s most endangered wildflowers and a true botanical gem that deserves our attention—and protection. This tiny perennial herb might be small in stature, but it carries enormous significance for desert plant enthusiasts ...

Rare plant alert!

Region: Conservation status by state

Status: S1: Status is uncertain but is somewhere between the following rankings: Critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘

Roosevelt Dam Rockdaisy: A Rare Arizona Treasure Worth Protecting

Meet the Roosevelt Dam rockdaisy (Perityle saxicola), one of Arizona’s most endangered wildflowers and a true botanical gem that deserves our attention—and protection. This tiny perennial herb might be small in stature, but it carries enormous significance for desert plant enthusiasts and conservation-minded gardeners.

What Makes This Little Rockdaisy Special?

The Roosevelt Dam rockdaisy is a charming forb that produces delicate, daisy-like flowers with crisp white petals surrounding sunny yellow centers. As a perennial herb, it lacks woody tissue but returns year after year from its ground-level growing points, making it a persistent (if petite) presence in the landscape.

Previously known by the synonym Laphamia saxicola, this little survivor has adapted to some seriously challenging conditions. It’s what botanists call a forb—basically a flowering plant that’s not a grass, sedge, or rush, and doesn’t develop woody stems.

Where Does It Call Home?

This rockdaisy is a true Arizona endemic, meaning it exists nowhere else on Earth except within the state’s borders. Its natural range is incredibly limited, centered around the Roosevelt Dam area in central Arizona.

The Reality Check: Rarity Status

Here’s the important part: Roosevelt Dam rockdaisy has a Global Conservation Status of S1, which means it’s critically imperiled. We’re talking about typically 5 or fewer known locations with very few remaining individuals (less than 1,000 plants total). This isn’t just rare—it’s on the edge of extinction.

If you’re considering adding this species to your garden, please source it only through reputable native plant societies, conservation organizations, or seed banks that work with ethically collected material. Never harvest from wild populations.

Growing Roosevelt Dam Rockdaisy: For the Committed Conservationist

Should you manage to obtain responsibly sourced seeds or plants, here’s what this little rockdaisy needs to thrive:

Perfect Growing Conditions

  • Climate zones: USDA hardiness zones 8b through 10a
  • Sunlight: Full sun exposure
  • Soil: Rocky, extremely well-draining soil that mimics its native cliff and crevice habitat
  • Water: Minimal once established—this is a true drought survivor
  • Drainage: Cannot tolerate standing water or heavy soils

Garden Design Ideas

Roosevelt Dam rockdaisy shines in specialized settings:

  • Rock gardens with excellent drainage
  • Xerophytic (drought-adapted) plant collections
  • Native plant demonstration gardens
  • Crevice gardens that mimic natural rock formations
  • Conservation-focused landscapes

Care and Maintenance

Once established, this rockdaisy is refreshingly low-maintenance:

  • Water sparingly—overwatering is more dangerous than drought
  • Ensure perfect drainage year-round
  • Avoid fertilizers, which can harm desert-adapted plants
  • Protect from excessive winter moisture
  • Allow natural dormancy cycles

Wildlife and Pollinator Benefits

Those cheerful daisy flowers aren’t just pretty—they provide nectar and pollen for small native bees and other beneficial insects. Every Roosevelt Dam rockdaisy plant becomes a tiny oasis for local pollinators.

The Bottom Line

Roosevelt Dam rockdaisy represents both an incredible opportunity and a serious responsibility. While it can make a meaningful addition to conservation-minded gardens, its critically imperiled status means we must approach it with respect and caution.

If you’re passionate about rare plants and committed to conservation, consider supporting organizations working to protect this species in the wild. And if you do grow it, think of yourself as a guardian of one of Arizona’s most precious botanical treasures.

Remember: with great rarity comes great responsibility. This little rockdaisy is counting on gardeners like you to help ensure its survival for future generations.

Roosevelt Dam Rockdaisy

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

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Perityle Benth. - rockdaisy

Species

Perityle saxicola (Eastw.) Shinners - Roosevelt Dam rockdaisy

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