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Cowbane

Oxypolis rigidior

Last reviewed: August 2026

Cowbane (Oxypolis rigidior)
Photo: (c) aarongunnar, some rights reserved (CC BY), uploaded by aarongunnar

Toxicity unknown

Cowbane (Oxypolis rigidior) 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.

Light

part sun

Water

high

Size

24"–60" H × 12"–24" W

Bloom

Jul, Aug, Sep

Native to

AL, AR, DE, FL and 23 more states

Pollinators

bees, beetles, flies

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 437 programs across 44 states, each with a link to the provider and the date we last checked it.

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Browse plants for this ecoregion

Ozark HighlandsPiedmontWestern Corn Belt PlainsNorth Central Hardwood ForestsDriftless AreaSoutheastern Wisconsin Till PlainsCentral Corn Belt PlainsEastern Corn Belt PlainsSouthern Michigan/Northern Indiana Drift PlainsHuron/Erie Lake PlainsNortheastern Coastal ZoneErie Drift PlainMiddle Atlantic Coastal PlainNorthern PiedmontSoutheastern PlainsBlue RidgeRidge and ValleyEastern Temperate ForestsCentral AppalachiansWestern Allegheny PlateauInterior PlateauInterior River Valleys and HillsSouthern Coastal PlainAtlantic Coastal Pine Barrens

Cowbane is a tall native perennial with clusters of small white flowers that bloom from summer into early fall. This wetland plant thrives in consistently moist to wet soils and partial sun conditions. It forms clumps that can reach up to 5 feet tall with an upright, somewhat formal appearance.

In an HOA neighborhood

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

Works well in: backyard only.

  • Name includes 'bane' which may concern neighbors
  • Requires consistently wet conditions uncommon in typical yards
  • Can appear wild and unstructured to conservative tastes

Wildlife value

The umbrella-shaped flower clusters attract a variety of pollinators including native bees, beetles, and flies during the summer blooming period.

Common questions

How much sun does Cowbane need?
Cowbane grows best in part sun conditions.
When does Cowbane bloom?
Cowbane blooms in July, August, and September.
Where is Cowbane native?
Cowbane (Oxypolis rigidior) is native to AL, AR, DE, FL and 23 more states, per the World Checklist of Vascular Plants (Kew).
What pollinators does Cowbane attract?
Cowbane draws bees, beetles, and flies.
Is Cowbane HOA-friendly?
Cowbane 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 the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

Ready to grow Cowbane? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.

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