Cystopteris bulbifera
Encyclopedia
Cystopteris bulbifera (bulblet bladderfern) is a low-growing rock fern
with creeping stems and narrow elongate deltate frond
s which grow to 75 cm (30 in), native to eastern North America
with two disjunct populations in the west. 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. 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.
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 C. laurentiana. Hybrids with C. protrusa have given rise to the allotetraploid species C. tennesseensis. The hybrid with C. reevesiana has given rise to the allotetraploid species C. utahensis. The hybrid with C. tenuis is known as C. Xillinoensis, an allotriploid. Also see Cystopteris hybrid complex
.
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
with creeping stems and narrow elongate deltate frond
Frond
The term frond refers to a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group...
s which grow to 75 cm (30 in), native to eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
with two disjunct populations in the west. It is found only on calcareous substrates such as limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
. It commonly festoons limestone cave
Cave
A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...
openings. While most commonly found on vertical rock faces, it also grows in rocky scree. 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.
This species is known to hybridize with Cystopteris fragilis
Cystopteris fragilis
Cystopteris fragilis is a species of fern known by the common names brittle bladderfern 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 fleshy petioles. Each leaf is divided into many pairs of...
, Cystopteris protrusa
Cystopteris protrusa
Cystopteris protrusa is a common fern of eastern North America. Throughout much of its range, it is the most common Cystopteris. It is commonly known as the lowland brittle fern or lowland fragile fern...
, Cystopteris reevesiana, and Cystopteris tenuis
Cystopteris tenuis
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 Bernh. var. mackayi Lawson....
. Hybrids with C. fragilis have given rise to the allohexaploid species C. laurentiana. Hybrids with C. protrusa have given rise to the allotetraploid species C. tennesseensis. The hybrid with C. reevesiana has given rise to the allotetraploid species C. utahensis. The hybrid with C. tenuis is known as C. Xillinoensis, an allotriploid. Also see Cystopteris hybrid complex
Cystopteris hybrid complex
-North American Cystopteris Hybrids:The diploid parent species within the genus include:*C. bulbifera*C. "hemifragilis" *C. protrusa*C. reevesianaThe hybrid species include:...
.