''Pentagramma triangularis,'' commonly known as the gold fern or the goldback fern, is a species of

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...

in the family

Pteridaceae Pteridaceae is a family of ferns in the order Polypodiales, including some 1150 known species in ca 45 genera (depending on taxonomic opinions), divided over five subfamilies. The family includes four groups of genera that are sometimes recogni ...

, native to Western North America, with highest abundance in the state of

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

. Its common name "goldback" refers to the light yellow color of the fern's protective coating which inhibits moisture loss. The gold texture appears as a dry powder that is excreted on the underside of the fern. The Latin

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''Pentagramma'' derives from "five lines" or "stripes" while ''triangularis'' derives from "three sided", describing the shape of the fern's broad triangular fronds.

Description

Like all ferns, ''P. triangularis'' does not produce flowers nor seeds, only spores. It has long smooth petioles (frond stems) that are anywhere from black to brown in color, and its fronds are bright to dark green on top with dark spore sacs (

sporangia A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cy ...

) on the leaf bottom surrounded by a lighter yellow excreted powdery substance. ''P. triangularis'' can grow to a height of 6 to 12 inches. In common with other '' Pentagramma'' species, the basal pinna has a characteristic asymmetry, with the basal secondary pinna on one side much (2 to 6-fold) longer than on the other. In response to dry conditions, the leaves curl up with the lower (spore) side outward, presumably to conserve water. Pentagramma triangularis JHT IMG 8395

Subspecies

*''P. triangularis'' subsp. ''semipallida'' (J. Howell) G. Yatsk. et al. — pale gold back fern *''P. triangularis'' subsp. ''triangularis'' Some taxa formerly considered subspecies of ''P. triangularis'' have been raised to species rank in '' Pentagramma''. * ''

Pentagramma maxonii ''Pentagramma'' is a small genus of North American ferns. Until 1990 members of this genus were included in ''Pityrogramma'', and there has been considerable disagreement regarding the species' taxonomy. In the most recent treatment, six diploid ...

'', previously ''P. triangularis'' subsp. ''maxonii'' * '' Pentagramma viscosa'', previously ''P. triangularis'' subsp. ''viscosa''

Distribution

The distribution of ''P. triangularis'' includes much of the west coast of North America and extends from Vancouver Island, British Columbia, to Baja California, Mexico, east to Arizona, and in the Blue Mountains of south eastern Washington. This species is also found on the Pacific island of Guadalupe off the Baja California shore, and plants there may represent an undescribed taxon.

Habitat

In California ''P. triangularis'' prefers shaded areas and is commonly found in rocky crevices and on north-facing slopes, in mixed evergreen and oak forests, and occasionally on dry brushy slopes. In more northerly locations, such as British Columbia and Washington State west of the

Cascade Range The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...

, it may be found in part shade or full sun mostly on rocky outcrops. It is found at elevations between sea level and 8,500 ft (2591 m).

Uses

The fronds are eaten by species such as the

Dusky-footed woodrat The dusky-footed woodrat (''Neotoma fuscipes'') is a species of nocturnal rodent in the family Cricetidae. They are commonly called "packrats" or "trade rats" and build large, domed dens that can reach several feet in height. Coyotes and other ...

. The Indigenous tribes of California would use the goldback fern as an analgesic treatment. The Karuk tribe would use the fern to treat pain related to childbirth, and the Miwok tribe would use the fern as a treatment for toothaches. Additionally, Yurok tribe children would use the fern to create body art with the golden powder.

References

External links

Calflora database: ''Pentagramma triangularis''USDA Plants Profile for ''Pentagramma triangularis'' (goldback fern)Jepson Manual Treatment for ''Pentagramma triangularis''''Pentagramma triangularis'' — UC Photo gallery
{{Taxonbar, from=Q7164993 Pteridaceae Ferns of California Ferns of Mexico Ferns of the United States Flora of the Northwestern United States Flora of the Southwestern United States Flora of British Columbia Flora of New Mexico Flora of the Cascade Range Flora of the Klamath Mountains Flora of the Sierra Nevada (United States) Flora of the California desert regions Flora of Mexican Pacific Islands Natural history of the California chaparral and woodlands Natural history of the California Coast Ranges Natural history of the Mojave Desert Natural history of the Peninsular Ranges Natural history of the San Francisco Bay Area Natural history of the Santa Monica Mountains Natural history of the Transverse Ranges Ferns of the Americas Flora without expected TNC conservation status