Pterocaulon pycnostachyum, with the common names dense-spike blackroot, fox-tail blackroot or coastal blackroot, is a plant species native to Alabama, Mississippi, North Carolina, Florida, Georgia, and South Carolina. It can be found in pinelands, ditches, depressions, and fields.Flora of North America v 19 p 476.Discover Life Pterocaulon pycnostachyum is a perennial herb up to 80 cm (31 inches) tall. Stems and the underside of leaves are covered with a thick, white layer of woolly hairs. Flower heads are crowded into a densely packed spike at the tips of the branches. Each head has as many as 50 small yellowish flowers. The plant is monoecious, meaning that some of the flowers have male stamens, while female pistils are in separate flowers in the same head.Cabrera, A. L. and A. M. Ragonese. 1978. Revisión del género Pterocaulon (Compositae). Darwiniana 21: 185–257.Elliott, Stephen. Sketch of the Botany of South-Carolina and Georgia 2(4): 324. 1824.Michaux, André. Flora Boreali-Americana 2: 126. 1803.Southeastern Flora
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 Pterocaulon pycnostachyum has left across the world's sequence archives.
At a glance
DNA specimens2
Marker genes3
GenBank sequences6
eDNA detections1
Countries1
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★rbcL2★ITS2
plant barcodefungal barcode
06Genome at a glanceCCDB
The complete instruction manualPterocaulon pycnostachyum 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 2 689≤1 km 467≤10 km 189>10 km 249
3 594 georeferenced · 700 without coordinates
Open the mapobservation + sensor4 294
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 accuracy21% within 1 km
≤100 m 9≤1 km 13≤10 km 30>10 km 55
107 georeferenced · 306 without coordinates
Open the institutions mapphysical evidence413
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 institutions34 of 48 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
Institution
Specimens
Tampa, US
120
Jena Microbial Resource Collectionlocation not on record
55
Miami, US
44
Bangkok, TH
28
Florida Museum of Natural History- Zoology, Paleontology & Paleobotanylocation not on record
23
Wuzhou, CN
16
Saint Louis, US
12
Valdosta State Universitylocation not on record
10
Bloomington, US
8
Tall Timbers Research Stationlocation not on record
7
Bronx, US
6
GAlocation not on record
6
BAYLUlocation not on record
5
Dover, US
5
Mississippi State, US
5
University of Stellenboschlocation not on record
5
Tuscaloosa, US
4
Knoxville, US
4
Burlington, US
4
Columbia, US
4
AUAlocation not on record
3
College Park, US
2
Clemson, US
2
Riverside, US
2
Asheville, US
2
Tempe, US
2
Chapel Hill, US
1
DOI/NPS, Little Rock Central High School National Historic Sitelocation not on record
1
Mexico City, MX
1
Chadron, US
1
Durham, US
1
DOI/NPS, Mississippi National River & Recreation Arealocation not on record
1
Wellington, NZ
1
Stockholm, SE
1
Williamsburg, US
1
Dekalb, US
1
Chongqing Museumlocation not on record
1
Flagstaff, US
1
Mérida, MX
1
Kew, GB
1
Richmond, US
1
Florida Museum of Natural Historylocation not on record
1
University of Southern Mississippilocation not on record
1
Due West, US
1
Taipei, TW
1
McWane Science Centerlocation not on record
1
Jackson, US
1
Moscow, US
1
48 institutions · 406 of 413 vouchered records shown · 7 without an institution code
09Environmental DNA1 detections
Where the DNA of Pterocaulon pycnostachyum 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 Foundation3 languages↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility4 707 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI1 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics2 specimens↗
NCBIUS National Library of Medicinesequences↗
Open Tree of LifeOpenTreephylogeny backbone↗
CCDBChromosome Counts DB · Tel Aviv U.genome & karyotype↗
PloiDBPloidy Databasegenome & karyotype
GLoBIGlobal Biotic Interactionsbiotic interactions↗