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Pentagramma glanduloviscida

Schuettp. & Windham

San Diego Silverback Fern

G4Apparently Secure Found in 2 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.1367673
Element CodePPADI0Q040
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumFilicinophyta
ClassFilicopsida
OrderFilicales
FamilyPteridaceae
GenusPentagramma
Concept Reference
Schuettpelz, E., K.M. Pryer, and M.D. Windham. 2015. A unified approach to taxonomic delimitation in the fern genus Pentagramma (Pteridaceae).Systematic Botany 40(3): 629-644.
Taxonomic Comments
Schuettpelz et al. (2015) describe Pentagramma glanduloviscida as distinct from Pentagramma maxonii.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2026-04-22
Change Date2026-04-22
Edition Date2026-04-22
Edition AuthorsSoteropoulos (2026)
Threat ImpactUnknown
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
Pentagramma glanduloviscida is a perennial fern found occurs in in shaded sites, near rocks or boulders. It occurs in southwestern North America, in the southern Peninsular Ranges in southwestern California , United States, and Baja California Norte, Mexico. There are over 200 occurrences. Little is known about threats or trends, but with a moderate range extent and large number of occurrences, this species is considered apparently secure.
Range Extent Comments
Pentagramma glanduloviscida occurs in southwestern North America, in the southern Peninsular Ranges in southwestern California (San Diego County), United States, and Baja California Norte, Mexico (Jepson Flora Project 2026). Range extent was estimated to be over 25,000 square kilometers using herbarium specimens and photo-based observations documented between 1994 and 2025 (RARECAT 2025, GBIF 2026, iNaturalist 2026, SEINet 2026).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are over 200 occurrences rangewide (RARECAT 2025, GBIF 2026, iNaturalist 2026, NatureServe 2026, SEINet 2026).
Threat Impact Comments
Although threats are not widely documented, this species is potentially threatened by stressors, including development and invasive species.
Ecology & Habitat

Habitat

Pentagramma glanduloviscida generally grows in shaded sites, near rocks or boulders (Jepson Flora Project 2026).
Terrestrial Habitats
Woodland - HardwoodWoodland - ConiferWoodland - MixedShrubland/chaparralBarrensBare rock/talus/scree
Other Nations (1)
United StatesN4
ProvinceRankNative
CaliforniaSNRYes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined———

—

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (2)
California (2)
AreaForestAcres
Eagle PeakCleveland National Forest6,481
Pine CreekCleveland National Forest503
References (6)
  1. Global Biodiversity Information Facility (GBIF). 2026. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2026).
  2. iNaturalist. 2026. Online. Available: https://www.inaturalist.org (accessed 2026).
  3. Jepson Flora Project (eds.) 2026. Jepson eFlora. Online. Available: https://ucjeps.berkeley.edu/eflora/ (accessed 2026).
  4. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  5. Schuettpelz, E., K.M. Pryer, and M.D. Windham. 2015. A unified approach to taxonomic delimitation in the fern genus <i>Pentagramma </i>(Pteridaceae).Systematic Botany 40(3): 629-644.
  6. Southwest Environmental Information Network (SEINet). 2026. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2026).