North America Native Plant

Fassett’s Water-starwort

Botanical name: Callitriche fassettii

USDA symbol: CAFA3

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Fassett’s Water-Starwort: A Rare Oregon Native for Specialized Water Gardens Meet Fassett’s water-starwort (Callitriche fassettii), one of Oregon’s most specialized and rare native aquatic plants. This delicate perennial forb might not be the showiest plant in the garden, but it holds a special place in the world of native water ...

Rare plant alert!

Region: Conservation status by state

Status: S1Q: Status is uncertain but is somewhere between the following rankings: Uncertain taxonomy: ⚘ 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) ⚘

Fassett’s Water-Starwort: A Rare Oregon Native for Specialized Water Gardens

Meet Fassett’s water-starwort (Callitriche fassettii), one of Oregon’s most specialized and rare native aquatic plants. This delicate perennial forb might not be the showiest plant in the garden, but it holds a special place in the world of native water gardening and wetland conservation.

What Makes This Plant Special?

Fassett’s water-starwort is a true Oregon endemic, meaning it’s found naturally nowhere else in the world except within Oregon’s borders. As a perennial forb, it’s an herbaceous plant that returns year after year without developing woody stems. This little aquatic gem forms delicate rosettes of tiny, star-shaped leaves that float gracefully on the water’s surface or grow submerged beneath it.

Where Does It Grow?

This rare native is exclusively found in Oregon, making it a true treasure of the Pacific Northwest. Its limited geographic range contributes to its special conservation status.

A Plant for Water Lovers Only

Here’s where things get interesting – Fassett’s water-starwort is classified as an obligate wetland species, which means it almost always occurs in wetlands. This isn’t a plant that tolerates occasional flooding; it absolutely requires aquatic conditions to thrive. Think of it as the ultimate water baby of the plant world.

The plant grows in:

  • Shallow, slow-moving streams
  • Natural ponds and pools
  • Seasonal wetlands
  • Spring-fed areas with consistent water flow

Important Conservation Alert

Before you get too excited about adding this plant to your water garden, there’s something crucial to know: Fassett’s water-starwort has a Global Conservation Status of S1Q, indicating it’s extremely rare and possibly at risk. This means if you’re interested in growing this species, it’s absolutely essential to source it responsibly from reputable native plant nurseries or conservation programs – never collect it from the wild.

Is This Plant Right for Your Garden?

Fassett’s water-starwort is definitely not for every gardener. This specialized species is best suited for:

  • Dedicated water gardeners with natural or naturalistic ponds
  • Wetland restoration projects in appropriate Oregon locations
  • Conservation-minded gardeners interested in preserving rare native species
  • Educational gardens showcasing Oregon’s unique flora

Growing Conditions and Care

If you’re committed to growing this rare beauty, here’s what it needs:

  • Water, water, everywhere: Consistent aquatic conditions are non-negotiable
  • Climate: Thrives in Oregon’s temperate climate (likely USDA zones 8-9)
  • Water quality: Prefers clean, unpolluted water
  • Sunlight: Likely tolerates both full sun and partial shade in aquatic settings
  • Maintenance: Minimal once established in appropriate conditions

Wildlife and Ecological Benefits

While Fassett’s water-starwort may not be a major pollinator magnet due to its tiny, inconspicuous flowers, it likely plays important ecological roles in its native aquatic habitats. These may include providing habitat for small aquatic creatures and contributing to the overall health of wetland ecosystems.

The Bottom Line

Fassett’s water-starwort is a plant for the true aquatic gardening specialist and conservation enthusiast. Its rarity makes it a responsibility as much as a privilege to grow. If you have the right conditions – namely, a permanent water feature – and can source it responsibly, this Oregon endemic could be a meaningful addition to a specialized native water garden.

For most gardeners interested in native aquatic plants, consider exploring other Oregon native water plants that are more readily available and less conservation-sensitive. But for those with the expertise and commitment to rare plant conservation, Fassett’s water-starwort offers a chance to participate in preserving one of Oregon’s most specialized botanical treasures.

Fassett’s Water-starwort

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

Callitrichales

Family

Callitrichaceae Link. - Water-starwort family

Genus

Callitriche L. - water-starwort

Species

Callitriche fassettii Schotsman - Fassett's water-starwort

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