![](http://www.phytoimages.siu.edu/CUBIC_IMAGES/phytoimages/paraman1/3_19_18/Upload19Mar18a/CystopterisTenuis1.jpg)
Cystopteris tenuis (Cystopteridaceae) image 128550 at PhytoImages.siu.edu
Of the other Cystopteris species in the state, the frond is most similar to C. protrusaC. tenuis, both of which also lack any glandular hairs and have fronds broadest above the base, but both of which grow in soil. C. protrusa is never on rock, its stem is usually green to straw-colored throughout and has a rhizome covered in yellowish hairs tha.
![](https://live.staticflickr.com/1518/26743799055_83d014cda7_b.jpg)
Cystopteris tenuis culvert Mackay's brittle fern growing i… Flickr
They are circular and arranged in a row along one or both sides of the pinnule midvein about halfway to the pinnule edge. An egg to cup-shaped, translucent tissue (indusium) partly covers the spores and is attached on inner curve but usually withers away as spores mature. Spores ripen to dark brown or black. Not all leaves have spores.
![](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Woodsiaceae/cystopteris-tenuis-le-ahaines-a.jpg)
Cystopteris tenuis (Mackay's fragile fern) Go Botany
Cystopteris fragilis × Cystopteris tenuis → Recognition of this nothospecies is generally missed during floristic inventories; it is most commonly misidentified as Cystopteris tenuis. It is intermediate between the two parental taxa, though on average larger than either, and possesses abortive spores.
![](http://minnesotawildflowers.info/udata/r9ndp23q/pd3/cystopteris-tenuis-152-11.jpg)
Cystopteris tenuis (Mackay's Fragile Fern) Minnesota Wildflowers
Vermont Leaf divisions the leaf blade is compound (divided into leaflets) the leaf blade is twice compound (divided into leaflets, which are further divided into leaflets) Plant growth form the leaves grow from a rhizome growing at or below the ground Spore -bearing leaflets
![](http://tcf.bh.cornell.edu/users/robbin/10_6_08/upload313/Cystopteris_tenuis01.jpg)
Cystopteris tenuis (Cystopteridaceae) image 33829 at
Etymology Tenuis means slender. Description Rhizome: short-creeping, covered with old stipe bases, scales tan to light brown, lanceolate. Frond: 40 cm high by 6 cm wide, deciduous, monomorphic, blade/stipe ratio: 3:2. Stipe: stipes --3 to 8-- clustered at stem apex, grooved, dark brown at base, straw-colored above, sparsely scaly at the base.
![](http://minnesotawildflowers.info/udata/r9ndp23q/pd3/cystopteris-tenuis-516-205302016.jpg)
Cystopteris tenuis (Mackay's Fragile Fern) Minnesota Wildflowers
Cystopteris tenuis Viewer. Page Index. Actions. file_download Download image 117 x 176 (JPEG) 234 x 352 (JPEG) 469 x 704 (JPEG) 938 x 1408 (JPEG) 1876 x 2817 (JPEG) 3753 x 5634 (JPEG) add Save to portfolios. link Copy Link save Cite this Item. About this Item Collection Locality. About this Specimen. Catalog Number
![](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Woodsiaceae/cystopteris-tenuis-so-rmoran.jpg)
Cystopteris tenuis (Mackay's fragile fern) Go Botany
Species Species include: [3] [4] Cystopteris alpina Cystopteris bulbifera - bulblet fern Cystopteris chinensis (Ching) R.Wei & X.C.Zhang (syn. Cystoathyrium chinense Ching) Cystopteris diaphana Cystopteris dickieana - Dickie's bladderfern Cystopteris douglasii - Douglas' bladderfern Cystopteris fragilis - brittle bladderfern
![](https://c1.staticflickr.com/1/976/39876693700_229b88b453_b.jpg)
Cystopteris tenuis (Mackay's fragile fern), Killingly, CT Flickr
Cystopteris tenuis (Michx.) Desv. upland brittle bladderfern. Additional References; Flora of North America (CYTE7) Integrated Taxonomic Information System (CYFRM) Integrated Taxonomic Information System (CYTE7) Lady Bird Johnson Wildflower Center Native Plant Information Network (CYTE7)
![](https://live.staticflickr.com/1623/23468283313_5305ae255f_b.jpg)
Cystopteris tenuis MacKay's fragile fern, growing in old m
Cystopteris fragilis is most often confused with C. tenuis in the east and C. reevesiana in the southwest. Habitat and geography, as well as the morphologic features discussed in the key, usually serve to separate these taxa.
![](https://minnesotawildflowers.info/udata/r9ndp23q/pd3/cystopteris-tenuis-516-4.jpg)
Cystopteris tenuis (Mackay's Fragile Fern) Minnesota Wildflowers
Scientific Name: Cystopteris tenuis (Michx.) Desv. Other Common Names: Cystoptère grêle (FR) , Mackay's brittle fern (EN) , upland brittle bladderfern (EN) Kingdom: Plantae Phylum: Filicinophyta Class:
![](http://minnesotawildflowers.info/udata/r9ndp23q/pd3/cystopteris-tenuis-516-14.jpg)
Cystopteris tenuis (Mackay's Fragile Fern) Minnesota Wildflowers
Cystopteris tenuis is common in eastern North America and less frequent at the northern and western perimeter of its range.
![](http://minnesotawildflowers.info/udata/r9ndp23q/pd3/cystopteris-tenuis-152-5.jpg)
Cystopteris tenuis (Mackay's Fragile Fern) Minnesota Wildflowers
Cystopteris tenuis (Mackay's Fragile Fern) Mackay's Brittle Fern, Upland Brittle Bladderfern Dryopteridaceae (Wood Fern) part shade, shade; average to moist; cliffs, talus slopes, ravines, rock outcrops, swamps, wooded banks, wooded slopes Pick an image for a larger view. See the
![](https://en-academic.com/pictures/enwiki/67/Cystopteris_tenuis-habitat.jpg)
Cystopteris tenuis
TENN Cystopteris tenuis: TENN-V-0009417: Cheatham: Tennessee: TENN Cystopteris tenuis: 31234100010246: Crittenden: Kentucky: 27 May 1969: Raymond Athey 644: EKY Cystopteris tenuis: Records per Page: View a List of All Ecological Communities. Plant Photos.
![](http://tcf.bh.cornell.edu/users/robbin/10_6_08/upload313/VT_trp_003.jpg)
Cystopteris tenuis (Cystopteridaceae) image 33852 at
Cystopteris Bernhardi, Neues J. Bot. 1(2): 26. 1805. Bladder fern, brittle fern [Greek kystos, bladder, and pteris, fern, alluding to the indusium, which is inflated when young]. 8 Cystopteris tenuis + Pinnae typically perpendicular to rachis, not curving toward blade apex; pinnae along distal 1/3 of blade deltate to ovate; margins of pinnae.
![](http://www.plantsystematics.org/users/robbin/10_1_07/upload227/IMG_0374.jpg)
Cystopteris tenuis (Cystopteridaceae) image 29475 at
Veins directed into teeth and notches. Indusia ovate to cup-shaped, without gland-tipped hairs. Spores spiny, usually 39--50 µm. 2 n = 168. Sporulating summer--fall.
![](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Woodsiaceae/cystopteris-tenuis-le-dcameron-a.jpg)
Cystopteris tenuis (Mackay's fragile fern) Go Botany
Discover thousands of New England plants Home Simple Key Full Key Dichotomous Key Help Genus: Cystopteris — fragile fern Past and present hybridization make the species of Cystopteris difficult to identify. Also, mature plants may be smaller than normal when growing in stressful habitats.