Sword Ferns
by Bruce Homer-Smith based on a Facebook Post by Roger Raiche

Sword Ferns (Polystichum spp.) all have “thumbs” that stick out at the base of each segment (pinna).

Western Sword Fern. Photo by Susan Mayne.

There are four common Sword Ferns in the Bay Area:

Photo Roger Raiche

Western Sword Fern is the most common. Cliff Sword Fern is similar, but its segments (pinae) are narrow and turned sideways, facing up.

Here is a closer view of Cliff and Western Sword Ferns:

Photo Roger Raiche

Dudley’s Sword Fern is lacy, with divided segments. California Sword Fern is a hybrid of Dudley’s and either Western or Cliff. Its appearance varies but shows characteristics of both its parents.

Here’s a closer view of California and Dudley’s Sword Fern:

Photo Roger Raiche

Have fun seeing if you can find all four.

Here’s Roger Raiche’s original post.

Corrections/Comments: bruce@PlantID.net