Mountain Bladderfern

Foodplant / spot causer
Herpobasidium filicinum causes spots on frond of Cystopteris montana

Cystopteris montana , the most distinctive of the Cystopteris in the flora, probably is allied to Asian species. Although this boreal species is restricted primarily to high latitudes, it occurs disjunctly at high elevations in Colorado, where its habitats are being threatened by development. Cystopteris montana does not hybridize with any other Cystopteris in the flora, but it has been implicated in the origin of the European allopolyploid C . alpina (Roth) Desvaux.

Stems long-creeping, cordlike, internodes 1--2(--4) cm, old petiole bases few, hairs absent; scales usually tan to light brown, ovate-lanceolate, radial walls tan to brown, thin, luminae tan. Leaves monomorphic, at stem apex but not tightly clustered, to 45 cm, sori production about equal on all leaves (fairly independent of season). Petiole dark brown to black at base, gradually becoming green or straw-colored distally, (1--)2--3 times length of blades, sparsely scaly throughout. Blade elongate-pentagonal, 3(--4)-pinnate-pinnatifid; rachis and costae lacking gland-tipped hairs or bulblets; axils of pinnae with occasional multicellular gland-tipped hairs. Pinnae ascending, typically at acute angle to rachis, only proximal pinnae occasionally curving toward blade apex, margins serrate; proximal pinnae pinnate-pinnatifid, inequilateral, basal basiscopic pinnule stalked, enlarged, base truncate to obtuse; distal pinnae deltate to ovate. Veins directed into notches. Indusia cup-shaped, apex truncate, hairs gland-tipped only along margin. Spores spiny, usually 37--42 µm. 2 n = 168.

Greenland; Alta., B.C., N.B., Nfld., N.W.T., N.S., Ont., Que., Sask., Yukon; Alaska, Colo., Mont.; Eurasia.

Sporulating summer--fall. Terrestrial in wet woods or along water courses; rare; 0--3500m.

Polypodium montanum Lamarck, Fl. Franç. 1: 23. 1779

The Sarmatic mixed forests ecoregion stretches from northwestern Europe to the Ural Mountains in Russia and represents one of the broadest longitudinal expanse of any ecoregion of the Earth. Dominant canopy species include Scots pine and Norway spruce (Picea abies) intermixed with some broadleaf species such as (Quercus robur). There are a number of ferns, shrubs, wildflowers, grasses and mosses that inhabit the mid-tier and forest floor. Common low-growing shrubs include Bilberry (Vaccinium myrtillus) and Heather (Calluna vulgaris).

Other understory associates to Mountain Bladderfern (Cystopteris montana) in the Sarmatic forests include the widespread Western Brackenfern (Pteridium aquilinum). Common mosses found in the more mesic soils are Broom Forkmoss (Dicranum scoparium), Stairstep Moss (Hylocomium splendens), Red-stemmed Feathermoss (Pleurozium schreberi), Ostrich Plume (Ptilium crista-castrensis) and Common Hair Moss (Polytrichum commune).

Example wildflowers or forbs seen in the forest understory are: Marsh Helleborine (Epipactis palustris), Red Campion (Silene dioica), Sand Catchfly (Silene conica), White Campion (Silene latifolia), Common Spotted Orchid (Dactylorhiza fuchsii) and Field Scabious (Knautia arvensis). In some fens within forest clearings the Marsh thistle (Cirsium palustre) is found.

Cystopteris montana, previously classified as Athyrium montanum, is a species of fern known by the common name mountain bladderfern. It occurs throughout the high latitudes of the Northern Hemisphere, in Eurasia, Greenland, and Alaska, and throughout Canada. It is also present in the higher elevations in Colorado farther south.

This fern produces a creeping, cordlike, scaly stem. The leaves are up to 45 centimeters long. The blades are borne on a petiole with a dark base and a light-colored end. The petiole is longer than the blade. The blade is pentagonal in shape and divided into leaflets which are subdivided into many lobed and toothed segments. The sori are covered in hairy, whitish, cup-shaped indusia.

This fern grows in moist mountain habitat, such as forests near streams.

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