Lactuca ludoviciana, the biannual lettuce, is a North American species of wild lettuce. It is widespread across much of central and western Canada and the western and central United States from Ontario west to British Columbia and south to Louisiana, Texas, and California. Most of the known populations are on the Great Plains; populations west of there may well represent naturalizations. Lactuca ludoviciana is a biennial herb in the dandelion tribe within the daisy family growing from a taproot a height of up to 150 cm (5 feet). The top of the stem bears a multibranched inflorescence with many flower heads. Each head contains 20-50 yellow ray florets but no disc florets. It has been seen to hybridize wildly with Lactuca canadensis, and it is difficult to differentiate between the two species.
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 Lactuca ludoviciana has left across the world's sequence archives.
At a glance
DNA specimens2
Marker genes2
eDNA detections1
Countries1
Marker genes sequenced
★ 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.
★rbcLa★ITS2
plant barcodefungal barcode
06Genome at a glanceCCDB
The complete instruction manualLactuca ludoviciana carries — its genome. We read it from three angles — how big it is, how the DNA is packed into chromosomes, and how completely it has been sequenced — and explain how to read each value as you go.
Chromosomes & ploidyhow the DNA is packaged
2n is the full chromosome count in a normal body cell; n is a gamete (egg or sperm), which carries half. Ploidy is how many complete chromosome sets each cell holds — 2× (diploid) is typical for animals, while higher levels (polyploidy) are common in plants. Click any value below to see the underlying records and sources.
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Coordinate accuracy87% within 1 km
≤100 m 235≤1 km 51≤10 km 10>10 km 31
327 georeferenced · 98 without coordinates
Open the mapobservation + sensor425
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 accuracy44% within 1 km
≤100 m 62≤1 km 81≤10 km 162>10 km 20
325 georeferenced · 180 without coordinates
Open the institutions mapphysical evidence505
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 institutions50 of 65 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
103
Austin, US
75
St. Paul, US
53
Fort Worth, US
45
Bronx, US
28
Madison, US
26
Durango, MX
15
Lincoln, US
14
Emporia, US
14
Chadron, US
11
Pullman, US
10
Spearfish, US
7
ASUlocation not on record
5
Brookings, US
4
Waverly, US
4
San Angelo, US
4
WTUlocation not on record
4
Austin, US
4
EL PASO, US
3
Davenport, US
3
University of Stellenboschlocation not on record
3
Giardini Botanici Hanburylocation not on record
3
DOI/NPS, Colonial National Historical Parklocation not on record
3
Flagstaff, US
3
DOI/NPS, Mississippi National River & Recreation Arealocation not on record
2
Corvallis, US
2
Pittsburg, US
2
Little Rock, US
2
Moscow, US
2
Durango, US
2
Vancouver, CA
2
US
2
IDElocation not on record
2
Mexico City, MX
2
Davis, US
2
Linares, MX
2
Angwin, US
2
CASlocation not on record
2
Riverside, US
2
Saint Louis, US
2
Instituto de Ecología Aplicada, Universidad Autónoma de Tamaulipaslocation not on record
1
Tacoma, US
1
Meguro Parasitological Museumlocation not on record
1
Grand Junction, US
1
Boise, US
1
IPA/SPlocation not on record
1
Jackson, US
1
DOI/NPS, Greenbelt Parklocation not on record
1
Provo, US
1
Denver, US
1
Bloomington, US
1
Chongqing Museumlocation not on record
1
San Luis Obispo, US
1
Denton, US
1
Burlington, US
1
Beijing, CN
1
Tempe, US
1
Mississippi State, US
1
Missoula, US
1
Phoenix, US
1
Knoxville, US
1
Albuquerque, US
1
Pocatello, US
1
University of Alberta Museumslocation not on record
1
Western Carolina Universitylocation not on record
1
65 institutions · 501 of 505 vouchered records shown · 4 without an institution code
09Environmental DNA1 detections
Where the DNA of Lactuca ludoviciana 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 found1
Studies independent surveys1
Signal confidence: weakweighed across independent studies, places & mapped detections
Where its DNA was found
0 of 1 detections have coordinates
Open the map0 countries0
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.
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 Facility947 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI1 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics2 specimens↗
GRIN TaxonomyUSDA-ARSdistribution & uses↗
Open Tree of LifeOpenTreephylogeny backbone↗
CCDBChromosome Counts DB · Tel Aviv U.genome & karyotype↗
PloiDBPloidy Databasegenome & karyotype
GLoBIGlobal Biotic Interactionsbiotic interactions↗