Cryptogramma cascadensis
Cryptogramma cascadensis is a species of fern known by the common names Cascade parsley fern and Cascade rockbrake.
Cryptogramma cascadensis | |
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Cryptogramma cascadensis on a rock wall near Frozen Lake on Mount Rainier, Washington, USA | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Division: | Polypodiophyta |
Class: | Polypodiopsida |
Order: | Polypodiales |
Family: | Pteridaceae |
Genus: | Cryptogramma |
Species: | C. cascadensis |
Binomial name | |
Cryptogramma cascadensis E.R.Alverson | |
Description
The plant forms a clump from a rhizome. It has two types of leaves. The sterile leaf is flat with lobed oval or diamond-shaped leaflets, and the fertile leaf is longer, with narrow, thick, fingerlike leaflets with edges curled under to cover the sporangia on the undersides. The leaves are deciduous.[1]
Taxonomy
Formerly lumped with Cryptogramma acrostichoides, C. cascadensis was described as a distinct species by Ed Alverson in 1989. The type specimen was collected growing on talus below Chair Peak, 5 km (3 mi) northwest of Snoqualmie Pass.[2]
Distribution and habitat
It is native to western North America from British Columbia to Montana to California, where it grows in the cracks and crevices of mountain talus slopes, especially in moist subalpine areas on volcanic or granite rocks.
References
- Hitchcock, C.L. and Cronquist, A. 2018. Flora of the Pacific Northwest, 2nd Edition, p. 56. University of Washington Press, Seattle.
- Alverson, Edward R. (1989). "Cryptogramma cascadensis, a new parsley-fern from western North America". American Fern Journal. 79 (3): 95–102. doi:10.2307/1547291. JSTOR 1547291.