Spinulose Shield Fern
"Spiny Wood Fern"
Polypodiaceae (Polypody Family)
General - large, clustered, erect, spreading perennial, usually 30 - 90 cm tall; from stout rhizomes covered with brown scales and remains of old stalk bases.
Leaves - triangular to oblong-lance-shaped in outline, 10 - 60 cm long, 2 - 3 times pinnate; 5 - 15 (sometimes 20) leaflet pairs; slightly alternate, lowest pair not symmetrical; 12 - 20 pairs of smaller divisions, slightly alternate; smallest segments softly spiny-toothed, stalks dark, usually shorter than leaves, with many brown scales, especially near base.
Spore clusters - rounded dots on veins, partly covered by rounded to kidney-shaped indusium.
Moist forests, thickets and openings; sometimes in swamps; widespread across boreal forest; rare in parkland, north and west to southwestern N.W.T. and western Alaska; more or less circumpolar.
Also called: D. carthusiana, D. spinulosa, D. dilatata, D. assimilis and D. expansa Spinulose shield fern includes a complex group of species that have undergone a taxonomic revision in recent years. Basically, it includes 2 major groups, broad spinulose shield fern (which includes D. dilatata, D. assimilis, and D. expansa), and narrow spinulose shield fern (which includes D. carthusiana, D. austriaca, and D. spinnolosa). Fragrant shield fern or fragrant cliff fern (D. fragrans) is so named because its leathery, evergreen leaves have a spicy aroma when dry. It is much smaller (to 30 cm tall), with dense tufts of narrow, usually twice pinnate leaves that are dark green above and rust-coloured below from dense, dry scales. It grows on cliffs, ledges, and rock slopes across our region, primarily north of 57 degrees N.
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