Northern Ontario Plant Database

Plant Description

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Polystichum braunii (Spenn.) Fée

En: Braun's hollyfern, eastern shieldfern, prickly shieldfern
Fr: polystic de Braun

Dryopteridaceae (Wood fern Family)

General: Perennial fern with similar sterile and fertile fronds (monomorphic), the thick, rhizome giving rise to a symmetrical crown of ascending fronds, to 1 m long.

Sterile Fronds: Bipinnate, with 20–40 pairs of pinnae; the frond elliptic to oblanceolate, tapering at both ends; the stalk of the frond (stipe) about 1/8–1/6 the length of the frond. The stipe and axis (rachis) of the frond are very scaly; the light brown scales are ovate at the base of the frond to linear above. Frond somewhat leathery (coriaceous) and slightly evergreen, lustrous above. Pinnae oblong to lanceolate, pointed (acute) at the apex; axes of the pinnae flattened and grooved, bearing linear scales. Pinnules ovate-lanceolate, with bases broadly tapering to a very short stalk, apex broadly pointed (obtuse) and bristle-tipped (apiculate), margins with bristle-tipped teeth (spinulose-serrate). The pinnule closest to the rachis on the upper half of each pinna is enlarged (auriculate) and points upward, towards the apex of the frond.

Fertile Fronds: Similar to sterile fronds, with sori borne on the lower surface of the fertile fronds. Sori are arranged in 2 rows, with 1 row on each side of the midrib; the indusium is circular, attached at the centre (peltate), to 1 mm in diameter, and margins are irregular (erose) to fringed (ciliate).

Habitat and Range: Moist, shaded conifer and mixedwood boreal forests; moist, shaded ravines and rocky slopes. Braun's holly fern is native to northeastern and coastal northwestern North America, as well as northern Eurasia (circumboreal disjunct). It is considered rare in most regions of Ontario, with a range that extends from eastern Ontario westward around Lake Superior, but it is locally common along the eastern shore of Lake Superior, between Sault Ste. Marie and Wawa.

Internet Images: This image of Polystichum braunii, from Matt Goff, shows the detail of the pinnules and the scaly rachis.

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