Olney's Threesquare
Schoenoplectus americanus
Found in tidal freshwater to brackish marshes. Weakley, Flora of the Southeastern United States (2025), South Central edition What its natural habitat tells you
Native to Mississippi. 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…
Rare or protected plant. Specialist conservation planting; excluded from routine garden suggestions. Plant caution source
Hidden from default planting suggestions. Wildlife value and native status remain unchanged.
At a glance
- Life cycle
- Perennial
- Bloom
- May to June
- Fruiting season
- June to September
Not yet recorded · Spread · Leaves
Recorded in 3 Mississippi counties.
Natural habitats
Places it grows wild. Not a planting requirement. Each habitat page lists the plants and wildlife also found there.
Coastal marshes flooded by salty or brackish tides.
Also found with this plant
Wildlife whose habitat models include habitats this plant grows in, in Mississippi. Shared habitat, not food. 118 animals.
- American AvocetRecurvirostra americana
- American BitternBotaurus lentiginosus
- American Black DuckAnas rubripes
- American CootFulica americana
- American CrowCorvus brachyrhynchos
- American OystercatcherHaematopus palliatus
- American PipitAnthus rubescens
- American White PelicanPelecanus erythrorhynchos
- American WigeonAnas americana
- AnhingaAnhinga anhinga
- Bald EagleHaliaeetus leucocephalus
- Bank SwallowRiparia riparia
- Barn SwallowHirundo rustica
- Belted KingfisherMegaceryle alcyon
- Black SkimmerRynchops niger
- Black-bellied Whistling-DuckDendrocygna autumnalis
- Black-crowned Night-heronNycticorax nycticorax
- Black-necked StiltHimantopus mexicanus
- Blue-headed VireoVireo solitarius
- Blue-winged TealAnas discors
- Boat-tailed GrackleQuiscalus major
- Bonaparte's GullChroicocephalus philadelphia
- Brewer's BlackbirdEuphagus cyanocephalus
- Brown PelicanPelecanus occidentalis
Who uses this plant?
12CaterpillarsGenus host records with ranges including MS
Genus host records with ranges including MS · Scirpus
- 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
- Neonympha areolataGeorgia Satyr, Helicta Satyr
- Neonympha mitchelliiMitchell's Satyr
- Bactra maiorina
- Cosmopterix attenuatella
- Cosmopterix ebriola
Show all 12
- Cosmopterix scirpicola
- Donacaula dispersella
0BeesSoutheastern regional records
0Specialist beesPollen specialists
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
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
| Mississippi rank | S1 |
|---|---|
| Global rank | G5 |
| MS 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
- NatureServe Explorer
- USDA PLANTS
- Vascular Plants of North Carolina (NC Natural Heritage Program)
- Weakley, Flora of the Southeastern United States (2025)
- Mississippi 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