''Cystopteris'' is a genus of

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...

s in the family Cystopteridaceae. These are known generally as bladderferns or fragile ferns. They grow in temperate areas worldwide. This is a very diverse genus and within a species individuals can look quite different, especially in harsh environments where stress stunts their growth. They hybridize easily with each other and identifying an individual can be challenging. In general these are

rhizomatous In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow ho ...

perennials which grow in rocks or soil. Their leaves are multiply pinnate, in that each leaflet is divided into smaller parts. The sori are usually rounded and covered in an inflated bladder-like indusium.

Species

Species include: *''

Cystopteris alpina ''Cystopteris alpina'' is a fern in the family Cystopteridaceae. It is closely related to '' C. fragilis'' and has been treated as conspecific with that species by many authors.Jonsell B (ed). (2000). "Flora Nordica: Volume 1 - Lycopodiacea to P ...

'' *''

Cystopteris bulbifera ''Cystopteris bulbifera'', with the common name bulblet fern, bulblet bladderfern, or bulblet fragile fern is a fern in the family Cystopteridaceae. Distribution The fern is native to eastern Canada, the Midwestern and Eastern United States, an ...

'' - 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 ''Cystopteris fragilis'' is a species of fern known by the common names brittle bladder-fern and common fragile fern. It can be found worldwide, generally in shady, moist areas. The leaves are up to 30 or 40 centimeters long and are borne on fles ...

'' - brittle bladderfern *'' Cystopteris laurentiana'' - St. Lawrence bladderfern *''

Cystopteris montana ''Cystopteris montana,'' previously classified as '' Athyrium montanum'', is a species of fern known by the common name mountain bladderfern. It occurs throughout the high latitudes of the Northern Hemisphere, in Eurasia, Greenland, and Alaska, a ...

'' - mountain bladderfern *'' Cystopteris protrusa'' - lowland bladderfern *'' Cystopteris reevesiana'' - Reeves' bladderfern *'' Cystopteris tennesseensis'' - Tennessee bladderfern *'' Cystopteris tenuis'' - upland brittle fern *'' Cystopteris utahensis'' - Utah bladderfern

Hybrids

''Cystopteris'' widely hybridizes internally. Its diploid parent species include: *'' C. bulbifera'' *''C. "hemifragilis"'' (an undiscovered or extinct diploid) *'' C. protrusa'' *'' C. reevesiana'' The

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

species include: *'' C. fragilis'' (''C. "hemifragilis"'' × ''C. reevesiana''; allotetraploid) *'' C. laurentiana'' (''C. bulbifera'' × ''C. fragilis''; allohexaploid) *'' C. tennesseensis'' (''C. bulbifera'' × ''C. protrusa''; allotetraploid) *'' C. tenuis'' (''C. "hemifragilis"'' × ''C. protrusa''; allotetraploid) *'' C. utahensis'' (''C. reevesiana'' × ''C. bulbifera''; allotetraploid) Non-species hybrids include: *''Cystopteris × illinoensis'' (''C. bulbifera'' × ''C. tenuis''; allotriploid) *''Cystopteris × wagneri'' (''C. tennesseensis'' × ''C. tenuis''; allo-allotetraploid) *''Cystopteris fragilis'' × ''Cystopteris tenuis'' (allo-allotetraploid) *''Cystopteris protrusa'' × ''Cystopteris tennesseensis'' (allotriploid)

References

* Lellinger, David B. ''A Field Manual of the Ferns & Fern-Allies of the United States & Canada''.

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded ...

Washington, DC ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan ...

. 1985.

External links

Jepson Manual TreatmentUSDA Plants ProfileFlora of North America
{{Taxonbar, from=Q881825 Polypodiales Fern genera