Taxon Report

Pentagramma rebmanii (Winner & M.G. Simpson) Schuettp. & Windham

Rebman's silverback fern

Print Report



Species Description:
Pentagramma rebmanii, commonly known as Rebman's silverback fern, is a perennial rhizomatous herb in the Pteridaceae that is found in California and elsewhere. It occurs within Chaparral, Cismontane woodland, and Riparian woodland, growing at elevations from 175 to 1760 meters. Pentagramma rebmanii is ranked 1B.3, Plants Rare, Threatened or Endangered in California and Elsewhere; Not very threatened in California.

  Classification

Scientific Name:
Pentagramma rebmanii (Winner & M.G. Simpson) Schuettp. & Windham
Common Name:
Rebman's silverback fern
Family: Pteridaceae
Element Code: PPADI0Q030
USDA Plants Symbol:
Synonyms/Other Names:

Ecology and Life History

Lifeform: perennial rhizomatous herb
Blooming Period:
Elevation: 175-1760 (575-5775)
General Habitats: Chaparral, Cismontane woodland, Riparian woodland
Microhabitat: Clay (sometimes), Decomposed granitic (sometimes), Gabbroic (sometimes), Granitic (often), Mesic, Rock crevices (sometimes), Rocky (often), Seeps, Slopes, Streambanks
Microhabitat Details: Seeps and other seasonally moist sites on ± shaded, generally north-facing, rocky slopes or canyon bottoms.

Occurrence Data from the CNDDB

Total Occurrences: 0
Element Occurrence Ranks:
   Excellent (A) 0
   Good (B) 0
   Fair (C) 0
   Poor (D) 0
   None (X) 0
   Unknown (U) 0
California Endemic:  False
California Counties and Islands: Name (Code)
Quads: Name (Quad Code)

Notes

Threats:
Potentially threatened by development.
Taxonomy:
Rare, unnamed polyploids resemble this diploid species. Pentagramma rebmanii has a dense, white farina (powdery-waxy secretion) on the lower leaf surface but differs from other Pentagramma taxa in having sparse, white farina on the upper leaf surface as well.

Selected References

Pentagramma rebmanii: Proposed Addition to CRPR 1B.3 (2024)
Madroño 54(4): 345 (2008)
Systematic Botany 40(3): 641 (2015)
Journal of the Botanical Research Institute of Texas 17(1): 28 (2023)
Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 20 January 2025].