Physematium scopulinum subsp. scopulinum

Rhizome and Frond Basics

Physematium scopulinum produces twice pinnate fronds that grow from a short, scaly rhizome. Most of its fronds are upright, measuring 10 to 30 cm long and up to 8 cm wide, and they range in color from medium to pale green.

Pinnae and Rachis Hair Characteristics

The pinnae and rachis are sparsely to moderately covered with sharply protruding long hairs that do not lie flat against the stem; some of these hairs have a globular gland at their tip. The hairy rachis is a key feature that sets this species apart from the closely related Physematium oreganum.

Rachis Morphology

The upper (adaxial) surface of the rachis is grooved.

Sori and Indusium Features

Small, round sori grow on the underside of the pinnae; these sori are initially partially covered by a narrowly lobed indusium.

Leaf Vernation

New leaves of this fern display circinate vernation, meaning they emerge tightly curled.

North American West Coast Distribution

Physematium scopulinum is widespread in mountain regions near the west coast of North America, ranging from southern Alaska to southern California.

Rocky Mountains and Isolated Distribution

It also grows across the Rocky Mountains from British Columbia to Colorado, with isolated populations present in northeastern North America.

Habitat Preferences

This species is most commonly found in sunny rocky habitats, including rock crevices, talus slopes, and rock ledges.