Cystopteris tenuis is sometimes known as Mackay's bladder fern or Mackay's fragile fern. It was long considered to be a part of the superspecies for fragile ferns, as Cystopteris fragilis (L.) Bernh. var. mackayi Lawson. C. tenuis in native habitat This species is an allotetraploid of hybrid origin (see Cystopteris hybrid complex). The parent diploid species are Cystopteris protrusa and the hypothesized Cystopteris hemifragilis, believed to be an extinct species. C. tenuis is known to hybridize with C. bulbifera to produce the hybrid C. Xillinoensis, with C. tennesseensis top produce the hybrid C. Xwagneri, and with C. fragilis and C. protrusa to produce unnamed hybrids (as per Flora of North America). Mackay's fragile fern grows on rock or in scree, generally in sheltered spots, in the northeastern United States. It may be distinguished from the somewhat similar Cystopteris tennesseensis by the fact that it grows on acid substrate, while the tennesseensis grows on calcareous substrate. The fronds of tenuis are broader, with generally alternate pinnae, while tennesseensis is narrower, with generally opposite pinnae.
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 Cystopteris tenuis has left across the world's sequence archives.
At a glance
DNA specimens9
Marker genes3
GenBank sequences10
eDNA detections9
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.
★matK1★rbcL9★rbcLa
plant barcode
06Genome at a glanceCCDB · GoaT
The complete instruction manualCystopteris tenuis 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.
Genome sizehow big the whole instruction manual is
Genome size8 337 450 000 bp
Measured in base pairs (bp) — the individual letters of DNA (human ≈ 3.2 Gb, a bacterium a few million). The chart places this genome on a logarithmic scale — each step to the right is ten times bigger — among reference organisms. Across species a bigger genome loosely tracks with larger cells, slower growth and lower-energy lifestyles (powered flight favours small genomes) — yet it does not imply more genes or a more advanced organism (the long-standing C-value paradox).
BACTERIUM Carsonella ruddii0.00016 Gb
FUNGUS0.04 Gb
INSECT0.25 Gb
HUMAN3.2 Gb
THIS GENOME Cystopteris tenuis8.34 Gb
WHEAT17 Gb
FERN Tmesipteris160.45 Gb
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.
CCDB · ipcn-api-dl — Haufler, C. H., M. D. Windham, D. M. Britton & S. J. Robinson. 1985. Triploidy and its evolutionary significance in Cystopteris protrusa. Canad. J. Bot. 63: 1855–1863.
CCDB · ipcn-api-dl — Haufler, C. H. & D. E. Soltis. 1986. Genetic evidence suggests that homosporous ferns with high chromosome numbers are diploid. Proc. Natl. Acad. Sci. U.S.A. 83: 4389–4393.
CCDB · Cave1956 — Wagner & Hagenah
Ploidy records — measured levels and diploid/polyploid inferences · click for sources
tetraploid1×GoaT · Kew Plant DNA C-values Database
GoaT · Kew Plant DNA C-values Database
07Deep time~2.67 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 origin2.67 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 053 records
Wild obs. + sensor652
Museum / vouchered1 401
Range
Area of Occupancy AOO6 300 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 accuracy69% within 1 km
≤100 m 307≤1 km 52≤10 km 18>10 km 145
522 georeferenced · 130 without coordinates
Open the mapobservation + sensor652
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 accuracy33% within 1 km
≤100 m 59≤1 km 215≤10 km 453>10 km 102
829 georeferenced · 572 without coordinates
Open the institutions mapphysical evidence1 401
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 institutions45 of 66 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
Institution
Specimens
St. Paul, US
215
Chongqing Museumlocation not on record
206
Burlington, US
140
Madison, US
128
Ann Arbor, US
99
US
77
Bronx, US
51
Minia, EG
37
Museo civico La Terra e l'Uomo di Crocetta del Montellolocation not on record
28
McWane Science Centerlocation not on record
22
Millersville, US
21
Wuzhou, CN
20
Québec, CA
17
Toronto, CA
16
Green Bay, US
14
Morgantown, US
14
Bloomington, US
14
Saint John, CA
12
Longwood Universitylocation not on record
11
University of Stellenboschlocation not on record
11
Flagstaff, US
9
Acadia Universitylocation not on record
8
WINlocation not on record
8
South Kensington, GB
8
Saint Louis, US
8
Lincoln, US
6
Chapel Hill, US
6
Phoenix, US
5
Chadron, US
5
Université Lavallocation not on record
5
ASUlocation not on record
5
Provo, US
4
Tampa, US
4
Philadelphia, US
4
Fort Worth, US
3
DOI/NPS, Colonial National Historical Parklocation not on record
3
University of Guelph, OAC Herbariumlocation not on record
3
Royal Botanical Gardenslocation not on record
2
Museum of the Rockieslocation not on record
2
Chicago, US
2
Logan, US
2
University of New Hampshirelocation not on record
2
Royal Ontario Museum, Green Plant Herbarium (TRT)location not on record
2
Whitewater, US
1
Austin, US
1
University of Alberta Museumslocation not on record
1
Adam Mickiewicz University in Poznańlocation not on record
1
Pittsburg, US
1
Universite de Montreal, L'Herbier Marie-Victorinlocation not on record
1
UFPRlocation not on record
1
Pullman, US
1
University of Wisconsinlocation not on record
1
Richmond, US
1
Durango, US
1
Decorah, US
1
LINUlocation not on record
1
Boise, US
1
Fayetteville, US
1
Victoria, CA
1
Claremont, US
1
Knoxville, US
1
Conway, US
1
Beijing, CN
1
Fargo, US
1
New Haven, US
1
Philadelphia, US
1
66 institutions · 1 282 of 1 401 vouchered records shown · 117 without an institution code
09Environmental DNA9 detections
Where the DNA of Cystopteris tenuis 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 found9
Studies independent surveys1
Countries2
Signal confidence: weakweighed across independent studies, places & mapped detections
Where its DNA was found
0 of 9 detections have coordinates
Open the map2 countries0
Rich mesic Sugar Maple forest. Aspect: W.Moist mossy ledge beneath overhang on S faci…Mesic mixed Hemlock forest on lower valley s…
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 median17.3 °C 11.4–21.0
Seasonal swing summer↔winter27.0 °C
Max temp (day)21.3 °C 16.1–25.6
Min temp (night)13.9 °C 8.10–17.1
Precipitation85.0 mm/mo 78.7–101
Air humidity57.5 % 56.7–59.9
Moisture balance-46.3 mm/mo -68.9–-37.8
Vapour deficit839 Pa 641–1,050
Wind speed3.60 m/s 2.50–5.80
Cloud cover40.1 % 36.7–45.8
CHELSA 1981–2010, ~9 km grid, at location & month of 8 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 053 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI9 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics9 specimens↗
NCBIUS National Library of Medicinesequences↗
Open Tree of LifeOpenTreephylogeny backbone↗
CCDBChromosome Counts DB · Tel Aviv U.genome & karyotype↗
GoaTGenomes on a Tree · Sangergenome & karyotype↗
GLoBIGlobal Biotic Interactionsbiotic interactions↗