Olney's Threesquare
Schoenoplectus americanus
In the Carolinas and Georgia, found in tidal freshwater to brackish marshes. Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition What its natural habitat tells you
Native to Arkansas (estimated). 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
No photograph yet. Looking for an old drawing…
At a glance
- Life cycle
- Perennial
- Bloom
- May to June
- Fruiting season
- June to September
Not yet recorded · Spread · Leaves
Recorded in 2 Arkansas counties.
Also found with this plant
Wildlife whose habitat models include habitats this plant grows in, in Arkansas. Shared habitat, not food. 119 animals.
- Acadian FlycatcherEmpidonax virescens
- Alder FlycatcherEmpidonax alnorum
- American Black DuckAnas rubripes
- American CootFulica americana
- American CrowCorvus brachyrhynchos
- American GoldfinchCarduelis tristis
- American KestrelFalco sparverius
- American RedstartSetophaga ruticilla
- American RobinTurdus migratorius
- American WoodcockScolopax minor
- Baltimore OrioleIcterus galbula
- Bank SwallowRiparia riparia
- Barred OwlStrix varia
- Bell's VireoVireo bellii
- Belted KingfisherMegaceryle alcyon
- Bewick's WrenThryomanes bewickii
- Black VultureCoragyps atratus
- Black-and-White WarblerMniotilta varia
- Black-billed CuckooCoccyzus erythropthalmus
- Black-crowned Night-heronNycticorax nycticorax
- Blue GrosbeakPasserina caerulea
- Blue JayCyanocitta cristata
- Blue-gray GnatcatcherPolioptila caerulea
- Blue-winged WarblerVermivora pinus
Who uses this plant?
7CaterpillarsGenus host records with ranges including AR
Genus host records with ranges including AR · 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
- Ledaea perditalisLost Owlet, 3-Stripe Cephalanthus caterpillar, Buttonbush Owlet
- Donacaula dispersella
27BirdsRecorded genus food-resource interactions; not a state feeding claim
Recorded genus food-resource interactions; not a state feeding claim · Scirpus
- Agelaius phoeniceusRed-winged Blackbird
- Anas platyrhynchosMallard
- Anthus rubescensAmerican Pipit
- Aythya affinisLesser Scaup
- Aythya americanaRedhead
- Aythya collarisRing-necked Duck
- Aythya marilaGreater Scaup
- Aythya valisineriaCanvasback
- Bucephala clangulaCommon Goldeneye
- Bucephala islandicaBarrow's Goldeneye
Show all 27
- Calcarius lapponicusLapland Longspur
- Calcarius pictusSmith's Longspur
- Cygnus buccinatorTrumpeter Swan
- Cygnus columbianusTundra Swan
- Fulica americanaAmerican Coot
- Gallinula galeataCommon Gallinule
- Loxia curvirostraRed Crossbill
- Mareca americanaAmerican Wigeon
- Mareca streperaGadwall
- Molothrus aterBrown-headed Cowbird
- Oxyura jamaicensisRuddy Duck
- Plectrophenax nivalisSnow Bunting
- Porzana carolinaSora
- Rallus limicolaVirginia Rail
- Spatula cyanopteraCinnamon Teal
- Spizelloides arboreaAmerican Tree Sparrow
- Sturnus vulgarisEuropean Starling
Direct food only: birds recorded eating this genus across North America. 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
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
- Bloom · “Late May to June” · Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition · Carolinas and Georgia
- Flower color · “Yellow or brown” · Lady Bird Johnson Wildflower Center
- Fruit begins · “June” · Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition · Carolinas and Georgia
- Fruit ends · “September” · Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition · Carolinas and Georgia
- Height · “It has erect, sharply triangular and deeply concave-sided culms growing up to 5 feet in height (1.5 m) [10,21].” · Fire Effects Information System: Schoenoplectus americanus (ranked first; Lady Bird Johnson Wildflower Center differs) · Source botanical description; original units and scope retained
- Life cycle · “Perennial” · Lady Bird Johnson Wildflower Center
- Light · “Partial shade; Full sun (documented habitat)” · Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition · Carolinas and Georgia
- Soil · “Water; Wet (documented habitat)” · Weakley, Flora of the Southeastern United States (2025), Carolinas & Georgia edition · Carolinas and Georgia
Also known as
Scirpus olneyi Gray; bulrush
Conservation status
| Arkansas rank | SNR |
|---|---|
| Global rank | G5 |
| AR status | Not verified |
| Federal status | Not verified |
Will it fit your yard?
Check this plant against your county, sun and soil moisture. Conditions are checked in your browser.
Sources
- USDA PLANTS
- Vascular Plants of North Carolina (NC Natural Heritage Program)
- Weakley, Flora of the Southeastern United States (2025)
- Arkansas occurrence source
- Shropshire & Tallamy 2025, Lepidoptera of North America north of Mexico, ZooKeys 1261 (ODbL)
- Noori, Seltmann & Orr 2026, A curated and integrated dataset for exploring global bee-plant interactions (GloBI), Zenodo, CC BY 4.0
- Smith, Bachelder, Russell, Morales, Mosher & Seltmann 2024, Bee-Specialization-Modeling v0.6.1 (specialist host table compiled from J. Fowler's pollen specialist bee lists), Zenodo, CC BY 4.0
- Hurlbert, Olsen, Sawyer & Winner 2021, Avian Diet Database, Scientific Data 8: 260 (CC0)
- Narango, Tallamy & Shropshire 2020, Few keystone plant genera support the majority of Lepidoptera species, Nature Communications

























