How much sun does Twoheaded Water-starwort need?

Twoheaded Water-starwort grows best in part shade conditions.

When does Twoheaded Water-starwort bloom?

Twoheaded Water-starwort blooms in May, June, July, and August.

Where is Twoheaded Water-starwort native?

Twoheaded Water-starwort (Callitriche heterophylla) is native to AL, AR, AZ, CA and 40 more states, per vouchered herbarium specimen records and regional native plant society lists.

Is Twoheaded Water-starwort toxic to livestock?

The USDA PLANTS Database does not flag Twoheaded Water-starwort as toxic to livestock.

Is Twoheaded Water-starwort HOA-friendly?

Twoheaded Water-starwort takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Twoheaded Water-starwort

Name: Pollinator Patch
Author: Pollinator Patch

Callitriche heterophylla

Last reviewed: August 2026

Toxicity unknown

Twoheaded Water-starwort (Callitriche heterophylla) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

The USDA PLANTS Database (opens in new tab) does not flag Twoheaded Water-starwort as toxic to livestock.

Light

part shade

Water

high

Size

2"–12" H × 2"–12" W

Bloom

May, Jun, Jul, Aug

Native to

AL, AR, AZ, CA and 40 more states

Before you buy

Your city may pay you to plant this

Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 452 programs across 44 states, each with a link to the provider and the date we last checked it.

Find rebates in your area

Browse plants for this ecoregion

Coast Range Puget Lowland Marine West Coast Forest Northwestern Forested Mountains Sierra Nevada Central California Foothills and Coastal Mountains Central California Valley Southern California Mountains Central Basin and Range Southern Rockies Arizona/New Mexico Mountains Southwestern Tablelands Central Great Plains Cross Timbers Edwards Plateau Texas Blackland Prairies East Central Texas Plains Western Gulf Coastal Plain South Central Plains Eastern Temperate Forests Ozark Highlands Central Irregular Plains Piedmont Western Corn Belt Plains Central Corn Belt Plains Eastern Corn Belt Plains Northeastern Highlands Northeastern Coastal Zone Northern Allegheny Plateau Erie Drift Plain Northern Forests Middle Atlantic Coastal Plain Northern Piedmont Southeastern Plains Blue Ridge Ridge and Valley Central Appalachians Western Allegheny Plateau Interior Plateau Interior River Valleys and Hills Mississippi Alluvial Plain Mississippi Valley Loess Plains Southern Coastal Plain Madrean Archipelago North American Deserts Atlantic Coastal Pine Barrens Southern California/Northern Baja Coast

Twoheaded water-starwort is a small aquatic annual that forms low mats in wet areas, ponds, or consistently moist soil. This delicate plant produces tiny inconspicuous flowers from May through August and requires constant moisture to thrive.

In an HOA neighborhood

Twoheaded Water-starwort takes more care to keep looking intentional in a front yard. Maintenance level: high. Consider it for backyard or mid-zone beds rather than the street edge.

Works well in: backyard only.

Requires standing water or bog conditions
Very small size makes it nearly invisible in landscaping
Annual lifespan means it disappears seasonally

Wildlife value

While this plant may provide some habitat for aquatic insects and small wildlife in water features, it has limited documented pollinator value.

Common questions

How much sun does Twoheaded Water-starwort need?: Twoheaded Water-starwort grows best in part shade conditions.
When does Twoheaded Water-starwort bloom?: Twoheaded Water-starwort blooms in May, June, July, and August.
Where is Twoheaded Water-starwort native?: Twoheaded Water-starwort (Callitriche heterophylla) is native to AL, AR, AZ, CA and 40 more states, per vouchered herbarium specimen records and regional native plant society lists.
Is Twoheaded Water-starwort toxic to livestock?: The USDA PLANTS Database does not flag Twoheaded Water-starwort as toxic to livestock.
Is Twoheaded Water-starwort HOA-friendly?: Twoheaded Water-starwort takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

If something looks wrong

Common plant problems, and what to check first

These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.

See all plant problem guides

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