Pentagramma glanduloviscida
San diego silverback fern, San Diego Silverback Fern
(c) Amy Huie, some rights reserved (CC BY) · licence
Family: Pteridaceae · Type: Perennial · Native
Pentagramma glanduloviscida (San diego silverback fern) is a native California perennial in the Pteridaceae family, recognized by sticky adaxial surface with stalked glands.
San diego silverback fern is a California native perennial found in southern Peninsular Ranges in San Diego County, growing in generally shaded sites near rocks and boulders at elevations of 100 to 400 meters. This distinctive fern features a blade that is adaxially sticky with conspicuous stalked glands and abaxially covered in dense white exudate. Growing with a unique rhizome structure, the fern's leaf is approximately longer than wide, with proximal pinnae smaller than the remainder of the leaf, creating a pinnately divided appearance. Its leaf blades are characterized by white glandular surfaces and an unusual sticky texture that sets it apart from other ferns. The fern's complex chromosome structure (2n=60) contributes to its specialized adaptation to rocky, shaded habitats in coastal southern California.
Identification and appearance
Key characters: 3 sympatric species; sticky adaxial surface with stalked glands is diagnostic
Habitat and range
Habitat: Generally +- shaded sites, near rocks, boulders
Elevation: 100-400 m
Outside California: nw Baja California
How to tell it apart
vs Pteridium: Pentagramma is small (<30 cm) and stays in rock crevices; Pteridium is tall (>50 cm) and spreads in open areas.; vs Polypodium: Pentagramma fronds are finely divided multiple times; Polypodium fronds are simple with one row of undivided leaflets.; vs Dryopteris: Pentagramma has golden/silver coating underneath; Dryopteris undersides are green with kidney-shaped spore covers.; vs Aspidotis: Pentagramma segments attach broadly; Aspidotis segments are bead-like with edges rolled under to protect spores.; vs Myriopteris: Pentagramma undersides are smooth or waxy; Myriopteris undersides are fuzzy with hairs or scales.
Frequently asked questions
Is Pentagramma glanduloviscida native to California?
Yes. Pentagramma glanduloviscida is native to California (recorded as native).
What plant family does Pentagramma glanduloviscida belong to?
Pentagramma glanduloviscida is in the Pteridaceae family, genus Pentagramma.
What habitat does Pentagramma glanduloviscida grow in?
Pentagramma glanduloviscida grows in Generally +- shaded sites, near rocks, boulders.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.