Polypodium calirhiza “California Licorice Fern” Polypodiaceae

Mt. Tamalpais State Park, Marin County, CA
December 29, 2015
Robert Niese

P. calirhiza is a hybrid of the California Polypody (P. californicum) and Licorice Fern (P. glycyrrhiza) that was formally recognized as a separate species in 1991. These hybrids persist as a unique species because of their doubled chromosome number (2n=148 instead of 74) which produces sterile back-crosses (2n=111). Speciation by this sort of genome duplication event is surprisingly common among plants. In coastal California, all three species often occur side-by-side, but P. californicum does not grow on other plants (as seen here) and P. glycyrrhiza has rhizomes with a pleasant, sweet licorice flavor (P. calirhiza has a disappointingly sweet, even acrid taste). This hybrid polypody occurs throughout California, north to Oregon, west of the Cascades and Sierras.

Blechnum spicant “Deer Fern” Polypodiaceae (Blechnacaeae)

Olympic National Park, WA
June 1, 2013
Robert Niese

This fern is mostly found west of the Cascades, but occasionally in Northern Idaho. I was surprised to learn that it has never been recorded in Montana. Blechnum ferns are known for conspicuously dimorphic fertile and infertile fronds. Tall fronds with skinny leaflets are typically spore-bearing like this one here.