Photo © Jill Blake CLICK PHOTO FOR A LARGER IMAGE

Phegopteris connectilis (Michaux) Watt

Northern Beechfern

Thelypteridaceae (Marsh Fern family)

Synonym: Thelypteris phegopteris (L.) Slosson

General Description: A light-green-colored fern with triangular-shaped fronds up to about 60 cm long arising from long, slender rhizomes. Plants are not evergreen, so they die back in the winter. New leaves can be produced from the rootstock any time during the growing season, and about half the frond length is comprised of the slender stalk. Each pinnately compound leaf has 10-25 pairs of sessile pinnae. The lowest several pairs of pinnae are the largest, while the upper ones are reduced and confluent. The lowermost pair are connected to the rachis at a downward angle. The leaves are beset with hairs, especially along the leaf margins and midveins. Sori are small and found near the margins of the pinnae lobes. There is no indusium.

Illustration.

Field Identification Tips: The non-evergreen fronds are scattered, not densely tufted along the rhizome. The slender petioles are as long or usually somewhat longer than the triangular-shaped blade. The lowermost pair of pinnae droop noticeably downward and are distinctly spaced from the next upper pair. The pinnae have margins and midveins that are distinctly hairy, not glabrous or chaffy.

Phenology: Produces spores in August and September.

Similar Species: Several ferns such as Dryopteris spp. can appear superficially similar. It is not uncommon for other ferns to occur in association with northern beechfern.

Photo © Robert Moseley CLICK PHOTO FOR A LARGER IMAGE

Habitat: Riparian western redcedar forests, and shaded, moist cliffs in valley to middle elevations in the mountains. It appears to have a narrow ecological amplitude along the fringe of its range in northern Idaho and northwestern Montana.

Global Distribution: Northern beechfern has an interruptedly circumboreal distribution. In North America it occurs from Alaska to Labrador, extending southward to many of the Great Lakes, Northeastern, and Appalachian region states. It is also known from several states in the Pacific Northwest.

Idaho Distribution: Boundary and northern Bonner counties, in the Purcell and Selkirk Mountains, and especially in the Priest Lake area.

References:

Flora North America Editorial Committee. 1993. Flora of North America, Vol. 2. Pteridophytes and Gymnosperms. Oxford University Press, Inc., New York. 475 pp.

Leavell, D. M., and L. J. Keunnen. 1993. Conservation assessment: Thelypteris phegopteris. USDA Forest Service, Northern Region, Kootenai National Forest. 13 pp. plus appendices.

Montana Natural Heritage Program. Montana rare plant field guide. Available at: http://nhp.nris.state.mt.us.