Fragile rock brake fern / Cryptogramma-stelleri

Not as sharp a photo as it should have been! Taken on 10 August 2013, when I went with a friend to Bow Lake in Banff National Park, along the Icefields Parkway. She showed me this small fern, growing on one of the huge rockslides near the edge of the lake, along the Bow Glacier trail. A great place for colourful lichens, too. This fern is also known as Steller's rock brake, Cliff Brake, and Slender Rock Brake.

"Stems creeping, few branched, slender, 1--1.5 mm diam., succulent, brittle; scales colorless, sparse, transparent-reticulate, ovate, 0.4 × 0.3 mm; stems shriveling in 2d year following emergence of leaves. Leaves scattered along stems, ephemeral (dying by late summer), soon shed; sterile leaves erect, 3--15 cm; fertile leaves erect, 5--20 cm; petioles, costae, and costules glabrous. Petiole dark brown in proximal 1/2 or less, becoming greenish distally, ca. 1 mm wide when dry, only slightly furrowed, glabrous. Blade broadly lanceolate to ovate-lanceolate, all pinnate-pinnatifid to 2-pinnate, herbaceous to membranous, thin; hydathodes superficial, often poorly developed or absent. Segments of sterile leaves ovate-lanceolate to fan-shaped, distal 1/2--1/3 shallowly lobed; segments of fertile leaves horizontal to ascending, often only partially differentiated from sterile leaves, lanceolate to linear, 8--25 × 2--4 mm; margins reflexed, forming continuous false indusia. Sporangia often in discrete sori. 2 n = 60.
New growth produced in spring, dying by late summer. Sheltered calcareous cliff crevices and rock ledges, typically in coniferous forest or other boreal habitats; 0--3000 m; Alta., B.C., N.B., Nfld., N.W.T., N.S., Ont., P.E.I., Que., Yukon; Alaska, Colo., Conn., Ill., Iowa, Maine, Mass., Mich., Minn., Mont., Nev., N.H., N.J., N.Y., Oreg., Pa., Utah, Vt., Wash., W.Va., Wis., Wyo.; Europe in ne former Soviet republics; Asia."

www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=2...