Cystopteris bulbifera
Introduction '''''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, and two disjunct populations in the Southwestern United States.It is found only on calcareous substrates such as limestone. It commonly festoons limestone cave openings. While most commonly found on vertical rock faces, it also grows in rocky scree.
Description ''Cystopteris bulbifera'' is a low-growing rock fern with creeping stems and narrow elongate deltate fronds which grow to 75 cm (30 in). ''C. bulbifera'' is unusual among ferns in producing bulblets along the bottom of the fronds. This is one of the easiest ''Cystopteris'' species to identify.Closeup of bulblet===Hybrids===This species is known to hybridize with ''Cystopteris fragilis'', ''Cystopteris protrusa'', ''Cystopteris reevesiana'', and ''Cystopteris tenuis''. Hybrids with ''C. fragilis'' have given rise to the allohexaploid species ''Cystopteris laurentiana''. Hybrids with ''Cystopteris protrusa'' have given rise to the allotetraploid species ''Cystopteris tennesseensis''. The hybrid with ''C. reevesiana'' has given rise to the allotetraploid species ''Cystopteris utahensis''. The hybrid with ''C. tenuis'' is known as ''C. × illinoensis'', an allotriploid. Also see Cystopteris hybrid complex.
References ===Further reading===*''A Field Guide to Ferns and their Related Families of Northeastern and Central North America'' — Cobb, Boughton. (1984), Peterson Field Guides series.
External links * Flora of North America: ''Cystopteris bulbifera'' —  distribution map* USDA Plants Profile for ''Cystopteris bulbifera''* Connecticut Botanical Society: ''Cystopteris bulbifera''