Asplenium vespertinum
Western spleenwort, western spleenwort, western spleenwort
(c) James C. Davis, some rights reserved (CC BY-SA) · licence
Family: Aspleniaceae · Type: Herb · Native
Conservation status: CNPS 4.2
Asplenium vespertinum (Western spleenwort) is a native California herb in the Aspleniaceae family, recognized by distinctive habitat preference for boulder bases.
Western spleenwort is a California native fern found in southern coastal California, the San Gabriel Mountains, and Peninsular Ranges in base areas of overhanging boulders at elevations of 200 to 1,000 meters. Producing dark red-brown to purple-brown stipes that are shiny and slender, this fern grows with clustered leaves 8 to 30 centimeters long. Its linear blade typically contains 20 to 30 pairs of pinnae, each pinna oblong and 5 to 12 millimeters long with shallowly lobed or toothed margins. The fern's delicate fronds are characteristically narrow, generally 1 to 2.5 centimeters wide, with pinnae that have a distinctive serrated appearance. Its sporangia form small sori generally 0.5 to 1.5 millimeters long, typically arranged in 2 to 6 pairs on each pinna.
Identification and appearance
Key characters: Geographically isolated; distinctive habitat preference for boulder bases
Habitat and range
Habitat: Base of overhanging boulders
Elevation: 200-1000 m
Outside California: northern Baja California
Conservation status
CNPS 4.2
How to tell it apart
vs Polystichum: Asplenium has linear to J-shaped sori; Polystichum has round sori with umbrella-like covers.; vs Rumex: Asplenium has fern fronds with sori underneath; Rumex has simple flowering plant leaves with papery sheaths.; vs Nephrolepis: Asplenium has free veins ending at margins; Nephrolepis has veins that form connecting loops.; vs Marsilea: Asplenium has typical fern fronds; Marsilea has four-parted clover-like leaves on creeping stems.; vs Blechnum: Asplenium sori are scattered along veins; Blechnum sori form continuous lines parallel to the midrib.
Frequently asked questions
Is Asplenium vespertinum native to California?
Yes. Asplenium vespertinum is native to California (recorded as native).
What plant family does Asplenium vespertinum belong to?
Asplenium vespertinum is in the Aspleniaceae family, genus Asplenium.
Is Asplenium vespertinum rare or endangered?
Asplenium vespertinum carries California Rare Plant Rank 4.2, state rank S4.
What habitat does Asplenium vespertinum grow in?
Asplenium vespertinum grows in Base of overhanging boulders.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos · CDFW CNDDB
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.