Flora of the Canadian Arctic Archipelago

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S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, L.J. Gillespie, A.K. Brysting, H. Solstad, and J.G. Harris

Woodsia R. Br.

English: Cliff ferns.

Woodsiaceae, Cliff-fern family.

Published in Prodr., 158. 1810.

Vegetative morphology. Plants 1–15(–20) cm high; perennial herbs; caespitose (loosely clustered). Only fibrous roots present. Roots black. Ground level or underground stems horizontal; stoloniferous; compact. Aerial stems not developed, fern leaves with long petioles arising from a rhizome. Leaves arising singly from creeping rhizomes (from the ground-level stems); alternate; dying annually and non-persistent, or marcescent. Petioles (10–)15–30(–50) mm long; glabrous, or hairy. Petiole hairs longer than the diameter of the petiole (if applicable). Leaf blades compound. Blades 30–150(–250) mm long, (2–)5–25(–35) mm wide, circinate when young (becoming linear or lanceolate mature fronds), with inconspicuous veins. Blade adaxial surface glabrous or hairy, hairs long-silky. Blade abaxial surface glabrous or hairy, hairs sparse or very dense. Blade margins slightly revolute, blades lobed. Blade margins crenate. Hydathodes present and conspicuous (slit-like), or present but inconspicuous. Blade apices obtuse. Leaflet arrangement pinnate.

Reproductive morphology. Sporangia in sori on the undersurface of the leaves. Indusia of narrow hair-like segments, one row of cells many times longer than wide, and longer than the sporangia.

Chromosome information. 2n = 78, 82, and 160 (probably).

Ecology and habitat. Substrates: ridges, cliffs; dry, moderately well-drained areas; rocks, gravel, sand; with low organic content.

North American distribution. Range in the Canadian Arctic Archipelago limited. Uncommon. Arctic, Low Arctic, alpine.

General notes. The English common name, cliff fern, is named for the English botanist Joseph Woods (Elven et al. 2003). Brown (1964) produced a monographic study of Woodsia.

Woodsia is a well-marked genus of ferns, with a base chromosome number of (X = 39 – 41). Cystopteris is probably the closest related genus. Woodsia is distinguished by articulate bases to the petioles and the accumulation of petiole bases from older leaves. The veins of the pinnae are obscure, and end in slit-like hydathodes before reaching the leaf margins. The indusia are multilobed, and the indusial segments are each a single row of cells that are much longer than wide. The Arctic Woodsia show close affinities to species found only in northern Eurasia (Windham 1993).

Illustrations. • Cliff fern. Characteristic Woodsia, cliff ferns, with simple pinnae and articulated (jointed) petioles that break off near the base. Nunavut, Rankin Inlet. CAN 565146.


This publication is available on the internet (posted May 2011) and on CD-ROM (published in 2007). These versions are identical in content, except that the errata page for CD-ROM is accessible on the main index page of the web version.

Recommended citation for the web-based version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. NRC Research Press, National Research Council of Canada, Ottawa. http://nature.ca/aaflora/data, accessed on DATE.

Recommended citation for the CD-ROM version of this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., Scott, P.J., Elven, R., LeBlanc, M.C., Gillespie, L.J., Brysting, A.K., Solstad, H., and Harris, J.G. 2007. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. [CD-ROM] NRC Research Press, National Research Council of Canada, Ottawa.

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