North America Native Plant

Bristleflower Collomia

Botanical name: Collomia macrocalyx

USDA symbol: COMA3

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Bristleflower Collomia: A Charming Pacific Northwest Native Worth Growing If you’re looking to add a touch of Pacific Northwest charm to your native garden, bristleflower collomia (Collomia macrocalyx) might just be the delightful annual you’ve been searching for. This humble yet attractive wildflower brings subtle beauty and ecological value to ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4: 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 ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Bristleflower Collomia: A Charming Pacific Northwest Native Worth Growing

If you’re looking to add a touch of Pacific Northwest charm to your native garden, bristleflower collomia (Collomia macrocalyx) might just be the delightful annual you’ve been searching for. This humble yet attractive wildflower brings subtle beauty and ecological value to gardens across the western United States.

What is Bristleflower Collomia?

Bristleflower collomia is an annual forb—basically a non-woody flowering plant that completes its entire life cycle in one growing season. As a native species to the lower 48 states, this plant has naturally adapted to thrive in its home range without any help from gardeners, making it a relatively low-maintenance addition to the right garden setting.

Where Does It Call Home?

This charming wildflower is native to the Pacific Northwest, specifically calling Idaho, Oregon, and Washington home. It’s perfectly adapted to the climate and growing conditions of this region, which means it can thrive in similar conditions elsewhere within USDA hardiness zones 4-8.

Why Consider Growing Bristleflower Collomia?

There are several compelling reasons to welcome this native annual into your garden:

  • Pollinator magnet: The small, tubular flowers in shades of pink to lavender attract butterflies, native bees, and other beneficial pollinators
  • Low maintenance: Once established, it requires minimal care and can even self-seed for next year’s display
  • Drought tolerance: Well-adapted to dry conditions, making it perfect for water-wise gardening
  • Native authenticity: Supports local ecosystems and provides habitat for native wildlife

Perfect Garden Settings

Bristleflower collomia shines in several garden styles:

  • Wildflower meadows and naturalized areas
  • Rock gardens where its compact form fits perfectly
  • Native plant gardens focused on regional flora
  • Cottage gardens seeking a more informal, wild look

Growing Conditions and Care

The beauty of growing native plants like bristleflower collomia lies in their adaptability to local conditions. Here’s what this little charmer prefers:

  • Sunlight: Full sun to partial shade
  • Soil: Well-drained soils are essential—this plant doesn’t like wet feet
  • Water: Drought tolerant once established, requiring minimal supplemental watering
  • Climate: Hardy in USDA zones 4-8

Planting and Care Tips

Growing bristleflower collomia is refreshingly straightforward:

  • Timing: Direct seed in fall for spring germination, or sow in early spring
  • Seeding: Scatter seeds directly where you want them to grow—they don’t typically transplant well
  • Spacing: Allow adequate spacing for air circulation
  • Maintenance: Minimal care required once established; deadhead spent flowers to encourage more blooms or leave them to self-seed

A Note About Conservation

Bristleflower collomia has a global conservation status of S3S4, which indicates it may be somewhat uncommon in parts of its range. If you’re interested in growing this species, make sure to source your seeds or plants from reputable native plant nurseries that collect responsibly. This ensures you’re not contributing to pressure on wild populations while still enjoying this lovely native in your garden.

The Bottom Line

Bristleflower collomia offers gardeners an excellent opportunity to grow a truly native species that supports local pollinators while requiring minimal fuss. Its delicate flowers and easy-going nature make it a wonderful choice for gardeners looking to create more sustainable, ecologically valuable landscapes. Just remember to source your plants responsibly, and you’ll be rewarded with a charming annual that brings a piece of the Pacific Northwest’s natural beauty right to your backyard.

Bristleflower Collomia

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

Solanales

Family

Polemoniaceae Juss. - Phlox family

Genus

Collomia Nutt. - trumpet

Species

Collomia macrocalyx Leiberg ex Brand - bristleflower collomia

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