Euphorbia albomarginata (formerly Chamaesyce albomarginata), whitemargin sandmat or rattlesnake weed, is a small low-growing perennial, in the spurge family (Euphorbia, Euphorbiaceae) native to desert, chaparral, and grassland habitats of southwestern North America, from southern and central California to Northern Mexico and Louisiana. It can be easily identified by its small size, dusty green leaves, very flattened growth pattern, and the white circular margin around the edge of its burgundy centered flowers. It is one of four members of the former Chamaesyce genus that are native to the Santa Monica Mountains, in addition to three species that have been introduced there, most of which share to some degree or other the white margin on the flower. As with other typical members of the Euphorbia family, it has a white milky sap, and is poisonous. It is one of only 11 members of the Euphorbia native to California, and one of four native to the Santa Monica Mountains.Flowering Plants of the Santa Monica Mountains, Nancy Drew, p. 106, 1985,
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 Euphorbia albomarginata has left across the world's sequence archives.
At a glance
DNA specimens6
Marker genes3
eDNA detections5
Countries2
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.
★matK★ITS★ITS2
plant barcodefungal barcode
06Genome at a glanceCCDB · GIFT · TreeOfSex
The complete instruction manualEuphorbia albomarginata 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 accuracy88% within 1 km
≤100 m 2 644≤1 km 347≤10 km 183>10 km 239
3 413 georeferenced · 1 215 without coordinates
Open the mapobservation + sensor4 628
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 accuracy42% within 1 km
≤100 m 129≤1 km 158≤10 km 287>10 km 105
679 georeferenced · 937 without coordinates
Open the institutions mapphysical evidence1 616
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 institutions66 of 89 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
Institution
Specimens
Riverside, US
260
San Diego, US
165
Claremont, US
155
Chicago, US
137
Bronx, US
103
Flagstaff, US
75
Santa Barbara, US
64
Philadelphia, US
62
ASUlocation not on record
40
Lubbock, US
39
Davis, US
38
Phoenix, US
36
Madison, US
25
Durango, MX
23
Mexico City, MX
22
St. Paul, US
20
Fort Worth, US
20
Ann Arbor, US
19
Saint Louis, US
17
Irvine, US
16
CASlocation not on record
15
San Luis Obispo, US
15
Pomona Collegelocation not on record
14
Emporia, US
12
San Angelo, US
12
Hermosillo, MX
11
Austin, US
11
Long Beach, US
10
Orem, US
8
Fullerton, US
8
Bloomington, US
8
La Paz, MX
6
BAYLUlocation not on record
6
Juriquilla, MX
6
Ensenada, MX
6
Moscow, US
5
DOI/NPS, Little Rock Central High School National Historic Sitelocation not on record
5
Culiacán, MX
5
Logan, US
5
Los Angeles, US
5
Severin-McDaniel Insect Collectionlocation not on record
4
University of Stellenboschlocation not on record
4
The University of Arizonalocation not on record
3
Pullman, US
3
Odawara, JP
3
Pittsburg, US
3
Provo, US
3
Texas Lutheran Universitylocation not on record
3
Guasave, MX
3
Arizona State University Biocollectionslocation not on record
2
Brisbane, AU
2
INFlocation not on record
2
Chapingo, MX
2
Eastern Nevada Landscape Coalitionlocation not on record
2
Tempe, US
2
Bangkok, TH
2
Dekalb, US
2
USFSlocation not on record
2
EL PASO, US
2
DOI/NPS, Colonial National Historical Parklocation not on record
2
Whitehorse, CA
2
DOI/NPS, Greenbelt Parklocation not on record
2
Tuscaloosa, US
2
Albuquerque, US
2
South Kensington, GB
2
San Jose State University, Museum of Birds and Mammalslocation not on record
2
Chongqing Museumlocation not on record
2
Mount Annan, AU
1
AUAlocation not on record
1
Chadron, US
1
Millersville, US
1
San Diego Natural History Museum, Herbariumlocation not on record
1
US
1
San Bernardino, US
1
San Diego Natural History Museumlocation not on record
1
GB
1
US
1
Chapel Hill, US
1
Tampa, US
1
Florida Museum of Natural History- Zoology, Paleontology & Paleobotanylocation not on record
1
Turlock, US
1
University of Alberta Museumslocation not on record
1
Weber State Universitylocation not on record
1
Kensington, AU
1
Wellington, NZ
1
Mississippi State, US
1
Denver, US
1
Henderson, US
1
Arcata, US
1
89 institutions · 1 596 of 1 616 vouchered records shown · 18 without an institution code
09Environmental DNA5 detections
Where the DNA of Euphorbia albomarginata 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 found5
Studies independent surveys1
Countries2
Signal confidence: weakweighed across independent studies, places & mapped detections
Where its DNA was found
0 of 5 detections have coordinates
Open the map2 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.
Modelled climatemodelled
−15°Ctemperature across detection sites+40°C
Temperature median24.4 °C 19.8–25.4
Seasonal swing summer↔winter16.8 °C
Max temp (day)31.2 °C 25.6–32.0
Min temp (night)17.6 °C 13.5–20.4
Precipitation71.2 mm/mo 22.6–108
Air humidity56.9 % 49.6–57.6
Moisture balance-100 mm/mo -147–-87.0
Vapour deficit1,423 Pa 1,012–1,565
Wind speed4.30 m/s 3.60–5.00
Cloud cover20.9 % 14.9–24.1
CHELSA 1981–2010, ~9 km grid, at location & month of 3 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 Foundation6 languages↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility6 244 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI5 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics6 specimens↗
GRIN TaxonomyUSDA-ARSdistribution & uses↗
Open Tree of LifeOpenTreephylogeny backbone↗
CCDBChromosome Counts DB · Tel Aviv U.genome & karyotype↗
giftgenome & karyotype
PloiDBPloidy Databasegenome & karyotype
Tree of SexTree of Sex Consortiumgenome & karyotype↗
GLoBIGlobal Biotic Interactionsbiotic interactions↗