Gymnocarpium disjunctum

Gymnocarpium disjunctum is a species of fern in the family Cystopteridaceae, commonly known as Pacific oak fern,[1] western oak fern,[2] or Pacific oakfern.[3]

Gymnocarpium disjunctum
Herbarium specimen of Gymnocarpium disjunctum

Secure  (NatureServe)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Division: Polypodiophyta
Class: Polypodiopsida
Order: Polypodiales
Suborder: Aspleniineae
Family: Cystopteridaceae
Genus: Gymnocarpium
Species:
G. disjunctum
Binomial name
Gymnocarpium disjunctum
(Rupr.) Ching

Description

Gymnocarpium disjunctum is a medium green fern with delicate-looking leaves that grows from a long slender creeping rhizome. The leaves do not arise from a central point but rather grow up individually from the creeping rhizome, often forming a loose grouping on the forest floor. The petioles (stipes) are 1-3 mm in diameter and 12-44 cm long with sparse glandular hairs distally. The petiole and blade midribs are brownish green to black in color. The leaves are bright to medium green and are 20-68 cm in length, with a broadly deltate blade, and are 3-pinnate to pinnatifid. The abaxial (lower) leaf surface and rachis are glabrous (hairless) or with sparse glandular hairs, and the adaxial (top) surface is glabrous. The largest pinnae are up to 18 cm long and are held nearly perpendicular to the rachis (leaf stem). The pinnae gradually decrease in size toward the distal end of the leaf, ending in a divided triangular leaflet at the tip. Sori form a single row on each side of the pinna midrib near the distal end of the leaf blade, becoming more crowded and less regularly arranged lower (proximally) on the blade.[1]

In the autumn, the leaves lose most of their color and become very pale, sometimes nearly pure white.[4]

Range

Gymnocarpium disjunctum is native to coastal northeast Asia, Alaska, and British Columbia and ranges south to Oregon and Washington, and to interior southern British Columbia, Idaho, Montana, and Wyoming.[1]

Habitat

Gymnocarpium disjunctum grows in shade in moist coniferous forests.[1]

References

  1. Hitchcock, C.L. and Cronquist, A. 2018. Flora of the Pacific Northwest, 2nd Edition, p. 58. University of Washington Press, Seattle.
  2. "Gymnocarpium disjunctum". Flora of North America. Retrieved 18 October 2022.
  3. "Pacific Oakfern". Encyclopedia of Life. Retrieved 18 October 2022.
  4. "iNaturalist research grade observation".
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.