North America Native Plant

Roundhead Chinese Houses

Botanical name: Collinsia corymbosa

USDA symbol: COCO2

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Roundhead Chinese Houses: A Rare California Native Worth Preserving Meet roundhead Chinese houses (Collinsia corymbosa), a charming little wildflower that’s as rare as it is beautiful. This annual native deserves a spot in your conservation-minded garden – but there’s an important catch we need to talk about first. What Makes ...

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) ⚘

Roundhead Chinese Houses: A Rare California Native Worth Preserving

Meet roundhead Chinese houses (Collinsia corymbosa), a charming little wildflower that’s as rare as it is beautiful. This annual native deserves a spot in your conservation-minded garden – but there’s an important catch we need to talk about first.

What Makes This Plant Special

Roundhead Chinese houses is a delicate annual forb that produces clusters of small, tubular flowers in lovely shades of blue to purple. The flowers are arranged in distinctive rounded heads that give this plant its common name. As a member of the plantain family, it shares some characteristics with its more common relatives but has its own unique charm.

This plant is a true California native, found only within the Golden State’s borders. It’s what botanists call an endemic species – meaning it naturally occurs nowhere else on Earth.

The Conservation Story: Why This Plant Needs Our Help

Here’s where things get serious. Roundhead Chinese houses has a Global Conservation Status of S1, which means it’s critically imperiled. With typically only 5 or fewer known occurrences and very few remaining individuals (less than 1,000), this little wildflower is hanging on by a thread.

If you’re considering adding this plant to your garden, you absolutely should – but only with responsibly sourced material. This means:

  • Purchase seeds or plants from reputable native plant nurseries that ethically propagate their stock
  • Never collect seeds or plants from wild populations
  • Consider participating in conservation seed collection programs if available

Growing Roundhead Chinese Houses Successfully

The good news is that once you have responsibly sourced seeds, roundhead Chinese houses isn’t particularly difficult to grow if you can mimic its preferred conditions.

Ideal Growing Conditions

  • Climate: USDA zones 9-10 (California’s Mediterranean climate)
  • Light: Partial shade to full sun
  • Soil: Well-drained soils; avoid heavy clay or constantly wet conditions
  • Water: Minimal irrigation once established; follows California’s natural wet winter/dry summer pattern

Planting and Care Tips

As an annual, roundhead Chinese houses completes its entire life cycle in one year, so timing is everything:

  • When to plant: Direct seed in fall to allow natural winter stratification
  • Germination: Seeds will germinate with winter rains and mild temperatures
  • Maintenance: Very low maintenance once established; avoid overwatering
  • Self-seeding: Allow plants to set seed for potential natural reseeding

Garden Design and Landscape Role

Roundhead Chinese houses works beautifully in:

  • Native wildflower gardens
  • Conservation gardens focused on rare California species
  • Naturalized areas that mimic California’s native grasslands
  • Educational gardens that showcase local biodiversity

Its modest size and delicate appearance make it perfect for intimate garden spaces where visitors can appreciate its subtle beauty up close.

Supporting Pollinators and Wildlife

Like many native California wildflowers, roundhead Chinese houses provides valuable resources for native pollinators, particularly small native bees. By growing this plant, you’re not just adding beauty to your garden – you’re providing habitat for the tiny creatures that depend on these native relationships.

The Bottom Line

Roundhead Chinese houses represents both an opportunity and a responsibility. It’s a chance to grow something truly unique and help preserve a piece of California’s natural heritage. But it requires us to be thoughtful gardeners who source our plants ethically and grow them with conservation in mind.

If you’re up for the challenge and can source seeds responsibly, this rare beauty could become a meaningful addition to your native plant collection – and a small but important contribution to its survival.

Roundhead Chinese Houses

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

Scrophulariales

Family

Scrophulariaceae Juss. - Figwort family

Genus

Collinsia Nutt. - blue eyed Mary

Species

Collinsia corymbosa Herder - roundhead Chinese houses

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