Aristida oligantha is a species of grass known by the common names prairie threeawn and oldfield threeawn. It is native to the United States and southern Canada, and it is known from northern Mexico. It is a grass of many types of habitat, and it grows easily in dry areas with sandy or gravelly soils. It appears in disturbed and burned areas and is sometimes a weed of roadsides and railroads. This is an annual forming clumps of branching gray-green and purple-tinted stems about 30 to 70 centimeters tall. The inflorescence is an open array of spikelets. The grain has three spreading awns, the central one reaching up to 7 centimeters long and the other two slightly shorter.
No narrative description available for this taxon yet.
A DNA barcode is a short, standardised stretch of genes that works like a fingerprint — enough to tell one species from another. Below is the molecular trace Aristida oligantha has left across the world's sequence archives.
At a glance
DNA specimens9
Marker genes5
GenBank sequences8
eDNA detections7
Countries2
The DNA barcodea real sequence read deposited for this species
★ the standard DNA barcode for this group — the short region actually read to tell this species apart. The rest are extra genes sequenced along the way.
★matK2★rbcL5★rbcLa★ITS1★ITS2
plant barcodefungal barcode
07Deep time~0.96 Ma lineage
How far back this lineage goes — and how we know. Everything here is measured in Ma, short for “mega-annum”: millions of years ago. The chart reads left to right like a calendar of the Earth, from the deep past on the left to today at the right edgetop to bottom like a core drilled through the Earth, from the deep past at the top down to today at the bottom.
At a glance
DNA clock origin0.96 Ma TimeTree
When this lineage existed
How to read this: the coloured strip along the bottomdown the left is the geological calendar — the standard epochs (Pliocene, Pleistocene…) every museum uses, shown so you can see which chapter of Earth's history this lineage lived in. This lineage is a young one, so the strip is zoomed in to epochs — the finer subdivisions inside a period. The orange marker is the DNA clock: DNA accumulates mutations at a roughly steady rate, so comparing this species' DNA with its relatives estimates when the lineage split off — independently of any fossil.
DNA clock origin
08Occurrence & distribution
Record type2 348 records
Wild obs. + sensor327
Museum / vouchered2 021
Origin
Native4
Range
Area of Occupancy AOO7 004 km²
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Coordinate accuracy82% within 1 km
≤100 m 182≤1 km 17≤10 km 5>10 km 38
242 georeferenced · 85 without coordinates
Open the mapobservation + sensor327
Museum / Voucheredphysical evidence
Backed by a physical specimen — a herbarium sheet, sample or voucher held in a collection. “Vouchered” means supported by material evidence, not just an observation.
Coordinate accuracy43% within 1 km
≤100 m 125≤1 km 371≤10 km 577>10 km 81
1 154 georeferenced · 867 without coordinates
Open the institutions mapphysical evidence2 021
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
10Collections & institutions
Holding institutions100 of 141 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
Institution
Specimens
Wuzhou, CN
305
International Salmonella Centre (W.H.O.)location not on record
123
Bronx, US
113
Fort Worth, US
100
Bloomington, US
98
Austin, US
80
Saint Louis, US
72
Davis, US
63
Chongqing Museumlocation not on record
53
Philadelphia, US
51
University of Stellenboschlocation not on record
47
Jackson, US
34
Columbia, US
33
Pittsburg, US
33
Williamsburg, US
33
DOI/NPS, Little Rock Central High School National Historic Sitelocation not on record
27
College Park, US
26
BAYLUlocation not on record
25
Tampa, US
24
Logan, US
24
Madison, US
22
Claremont, US
21
Fayetteville, US
19
Allentown, US
19
Corvallis, US
19
DOI/NPS, Greenbelt Parklocation not on record
18
Ann Arbor, US
18
Canadian Department of Agriculturelocation not on record
17
Chadron, US
14
Chapel Hill, US
12
Riverside, US
12
Millersville, US
12
Philadelphia, US
12
EL PASO, US
11
Tuscaloosa, US
11
Knoxville, US
11
Bangkok, TH
11
Lincoln, US
10
GB
10
Jena Microbial Resource Collectionlocation not on record
10
Little Rock, US
10
New Haven, US
10
Davenport, US
9
Denver, US
9
US
9
CASlocation not on record
9
DOI/NPS, Mississippi National River & Recreation Arealocation not on record
8
Emporia, US
7
AUAlocation not on record
7
ASUlocation not on record
7
Dekalb, US
7
Stephenville, US
6
Flagstaff, US
6
Phoenix, US
6
Denton, US
6
Mississippi State, US
6
Edmonton, CA
6
San Luis Obispo, US
5
Santa Barbara, US
5
Auckland, NZ
5
St. Paul, US
5
Lubbock, US
5
Provo, US
5
University of Southern Mississippilocation not on record
5
Burlington, US
4
Oskarshamn, SE
4
Pullman, US
4
Angwin, US
4
Norfolk, US
4
San Angelo, US
4
Arcata, US
4
University of New Hampshirelocation not on record
4
Maryland Department of Natural Resourceslocation not on record
4
US
3
Green Bay, US
3
Weber State Universitylocation not on record
3
Henderson State Universitylocation not on record
3
Florida Museum of Natural History- Zoology, Paleontology & Paleobotanylocation not on record
3
Moscow, US
3
Fullerton, US
3
San Diego, US
3
Asheville, US
3
Beijing, CN
3
Musee des Dinosaures d'Esperaza (Aude)location not on record
3
Albuquerque, US
2
Minia, EG
2
Portland, US
2
New Brunswick, US
2
GAlocation not on record
2
Kew, GB
2
Wlocation not on record
2
Staten Island, US
2
Caldwell, US
2
Museum of the Rockieslocation not on record
2
Boise, US
2
Vancouver, CA
2
Russellville, US
2
Macomb, US
2
DOI/NPS, Colonial National Historical Parklocation not on record
2
Kirksville, US
2
James F. Matthews Center for Biodiversity Studieslocation not on record
2
Texas Lutheran Universitylocation not on record
2
US
2
Tall Timbers Research Stationlocation not on record
1
Toronto, CA
1
Kingston, US
1
Nantes Culture Collectionlocation not on record
1
WTUlocation not on record
1
Northridge, US
1
USFSlocation not on record
1
Missouri Department of Conservationlocation not on record
1
Texas A&M Universitylocation not on record
1
Chicago, US
1
Dresden, DE
1
Leiden University Medical Centerlocation not on record
1
Jefferson City, US
1
Springfield, US
1
Cambridge, US
1
Clemson, US
1
China Agricultural Universitylocation not on record
1
Due West, US
1
Barcelona, ES
1
Istituto Agrario Castelnuovolocation not on record
1
Spearfish, US
1
Moscow State Universitylocation not on record
1
Museo civico La Terra e l'Uomo di Crocetta del Montellolocation not on record
1
Cenargenlocation not on record
1
La Paz, MX
1
Wellington, NZ
1
Ashland, US
1
Salvador, BR
1
Pocatello, US
1
Brasília, BR
1
McWane Science Centerlocation not on record
1
Bureau of Land Management, Medford District Officelocation not on record
1
Jurica-Suchy Nature Museumlocation not on record
1
Durham, US
1
Grand Junction, US
1
Mohonk Preservelocation not on record
1
Durham, US
1
Conway, US
1
141 institutions · 1 961 of 2 021 vouchered records shown · 58 without an institution code
09Environmental DNA7 detections
Where the DNA of Aristida oligantha was picked up in samples of water, soil or air — nobody saw the organism, only its DNA left behind. A trace is a clue that the species was near, not a confirmed sighting.
Signal
Detections DNA found7
Studies independent surveys1
Countries1
Signal confidence: weakweighed across independent studies, places & mapped detections
Where its DNA was found
0 of 7 detections have coordinates
Open the map1 country0
prairie remnant along railway; dry ground in…dry open ground near tracks, locally abundan…
How strong is each trace?
DNA read depthRead counts were not reported for this species — the map shows presence only, not how strong each trace was.
Modelled climatemodelled
−15°Ctemperature across detection sites+40°C
Temperature median16.2 °C 13.2–19.2
Seasonal swing summer↔winter27.0 °C
Max temp (day)22.3 °C 19.2–25.4
Min temp (night)12.0 °C 9.00–15.0
Precipitation84.2 mm/mo 80.5–87.8
Air humidity56.8 % 56.4–57.2
Moisture balance-47.2 mm/mo -54.2–-40.1
Vapour deficit878 Pa 762–994
Wind speed5.70 m/s 5.60–5.80
Cloud cover32.9 % 29.8–35.9
CHELSA 1981–2010, ~9 km grid, at location & month of 2 detection points · median with p10–p90 · reflects where sampling happened, not only the true niche
How to read this: each dot is one detection of this species' DNA in an environmental sample. The confidence meter weighs how many independent studies and places back up the signal — one detection in one study is a hint; many across several studies is solid. Records dated before 2008 (when eDNA methods began) are treated as likely mislabeled and left off the map.
WikipediaWikimedia Foundation2 languages↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility2 348 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI7 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics9 specimens↗
NCBIUS National Library of Medicinesequences↗
GRIN TaxonomyUSDA-ARSdistribution & uses↗
Open Tree of LifeOpenTreephylogeny backbone↗
GLoBIGlobal Biotic Interactionsbiotic interactions↗