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Olney's Threesquare

Schoenoplectus americanus

Found in tidal freshwater to brackish marshes. Weakley, Flora of the Southeastern United States (2025), Northern Tier edition What its natural habitat tells you

45
Good

Native to Virginia. How scores work Is it native here?

Profile 76%

Height
It has erect, sharply triangular and deeply concave-sided culms growing up to 5 feet in height [10,21].
Light
Partial shade, Full sun
Soil moisture
Wet to standing water
Will it fit your yard?

At a glance

Life cycle
Perennial
Bloom
May to June
Fruiting season
June to September

Not yet recorded · Spread · Leaves

Recorded in 27 Virginia counties and cities.

Natural habitats

Places it grows wild. Not a planting requirement. Each habitat page lists the plants and wildlife also found there.

Salt and brackish marshes

Coastal marshes flooded by salty or brackish tides.

All habitats

Also found with this plant

Wildlife whose habitat models include habitats this plant grows in, in Virginia. Shared habitat, not food. 132 animals.

Widespread birds also seen here (63)

Found in many habitats here, so not listed above.

All wildlife of Virginia

Ecological relationships

Who uses this plant?

What these records mean

13CaterpillarsGenus host records with ranges including VA

Genus host records with ranges including VA · Scirpus

  • Apamea sordensBordered Apamea, Rustic Shoulder-Knot
  • Bactra furfuranaRush Bactra
  • Bactra verutanaJavelin Moth
  • Euphyes dionDion Skipper, Sedge Skipper
  • Globia oblongaOblong Sedge Borer Moth, Large Noagria
  • Globia subflavaYellow Sedge Borer, Yellowish Nonagria, Subflava Sedge Borer
  • Helotropha reniformisAmerican Crescent Borer, Reniform Celaena, Reniform Helotropha
  • Ledaea perditalisLost Owlet, 3-Stripe Cephalanthus caterpillar, Buttonbush Owlet
  • Meropleon diversicolorMulticolored Sedgeminer
  • Neonympha mitchelliiMitchell's Satyr
Show all 13
  • Bactra maiorina
  • Cosmopterix scirpicola
  • Donacaula dispersella
Shropshire & Tallamy 2025, Lepidoptera of North America north of Mexico, ZooKeys 1261 (ODbL)
0BeesSoutheastern regional records
0Specialist beesPollen specialists
7BirdsRecorded eating Schoenoplectus in Virginia

Diet records by plant genus, from studies across North America. Not a record from this state. Birds whose range includes Virginia, most records first.

Avian Diet Database (Hurlbert Lab)

Direct food only. Caterpillars on host plants also feed nesting birds. NC Native Plant Society: butterfly gardening

No records yet · Ants · Beetles · Flies · Adult butterflies / moths · Other wasps · Other insects

Birds that eat Schoenoplectus 7

Diet records by plant genus, from studies across North America. Not a record from this state. Avian Diet Database (Hurlbert Lab), CC0 1.0.

Growing and identification

Plant details

Family
Cyperaceae
Flower color
Yellow or brown
Fruit begins
June
Fruit ends
September

Safety has not been reviewed for this plant; check toxicity and thorns before planting.

Growing sources and scope
Also known as

Scirpus olneyi Gray; bulrush

Conservation status

Virginia rankS4
Global rankG5
VA statusNot verified
Federal statusNot verified

Conservation source Global and federal source

In your garden

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How to check your spot

Sources