Hybrids of Northern Temperate Cystopteris Species

Species are listed in the left-hand column by letters, which also appear in the column headings. The column headed by an asterisk denotes those species which have hybrid origins, and gives the number of that hybrid.

Table of diploid Cystopteris species

Species   a. b. c. d.
a. Cystopteris bulbifera* (Linnaeus) Bernhardi    
b. Cystopteris "hemifragilis"#      
c. Cystopteris protrusa** (Weatherby) Blasdell
d. Cystopteris reevesiana*** Lellinger

#"hemifragilis" is a provisional name for an apparently extinct species with no known fossil record
*also see 11, 12, 20
**also see 15, 17
***also see 16, 19

Primary hybrids (all tetraploid species):

1. Cystopteris fragilis (Linnaeus) Bernhardi: C. "hemifragilis" X C. reevesiana; also see 12, 13, 14, 18, 19, 21
2. Cystopteris tennesseensis Shaver: C. bulbifera X C. protrusa; also see 13, 15, 20
3. Cystopteris tenuis (Michaux) Desvaux: C. "hemifragilis" X C. protrusa; also see 11, 13, 14, 17
4. Cystopteris utahensis Windham & Haufler: C. reevesiana X C. bulbifera; also see 16

Secondary hybrids:

11. Cystopteris Xillinoensis R.C. Moran: C. bulbifera X C. tenuis; allotriploid
12. Cystopteris laurentiana (Weatherby) Blasdell: C. bulbifera X C. fragilis; allohexaploid: see also 18
13. Cystopteris Xwagneri R.C. Moran: C. tennesseensis X C. tenuis; allo-allotetraploid
14. Unnamed hybrid: C. fragilis X C. tenuis; allo-allotetraploid
15. Unnamed hybrid: C. protrusa X C. tennesseensis; allotriploid
16. Unnamed hybrid: C. reevesiana X C. utahensis; allotriploid
17. Unnamed hybrid: C. protrusa X C. tenuis: allotriploid
18. Unnamed hybrid: C. fragilis X C. laurentiana: allopentaploid
19. Unnamed hybrid: C. fragilis X C. reevesiana: allotriploid
20. Unnamed hybrid: C. bulbifera X C. tennesseensis: allotriploid

Notes: Some authors treat Cystopteris dickeana as a synonym of C. fragilis, but it may be a separate species; there is a supposed hybrid reported between the two, C. Xmontserratii. Cystopteris Xchristii Hahne is a hybrid between C. fragilis X C. myrrhidifolia? Cystopteris montana (Lam.) Bernh. ex Desv. may be a parent of the European species Cystopteris alpina (Jacq.) Desv.