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.

Equisetum arvense “Common Horsetail” Equisetaceae

Lolo National Forest, Bitterroot Mountains, MT
May 10, 2015
Robert Niese

Horsetails were once abundant, diverse organisms, but today all surviving members of this ancient clade are restricted to a single genus with a worldwide distribution. This particular stalk is a fertile, strobilus-bearing stem. Their infertile counterparts look almost nothing alike!

Oxalis oregana “Oregon Wood-sorrel” Oxalidaceae
with Polystichum munitum “Western Sword Fern” Dryopteridaceae

Olympic National Park, WA
June 5, 2013
Robert Niese

This is a common scene throughout the Olympic Peninsula where rainforest floors are literally carpeted with these two species. Both species are edible, but Oxalis is by far my favorite of the two. There’s nothing quite like munching on Oxalis straight from the trail while hiking through a PNW rainforest.

Adiantum pedatum (aleuticum) ”Northern Maidenhair Fern” Pteridaceae

Olympic National Park, WA
June 6, 2013
Robert Niese

One of my favorite Pacific Northwest Plants, these beautiful ferns are most common in very wet areas of our lowland forests. They are particularly fond of waterfalls.

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.