Polystichum braunii (Spenner) Fée

Braun's hollyfern, Prickly shield fern

Etymology Alexander Carl Heinrich Braun, 1805-1877, German professor of botany.
Description Rhizome: short, stout, erect, very scaly.
Frond: 70 cm high by 22 cm wide, evergreen, monomorphic, blade/stipe ratio: 4: 1 to 6:1.
Stipe: grooved, scales silvery at first, then light brown, dense at base, vascular bundles: 5-7, in an arc.
Blade: 2-pinnate, ovate, broadest at the middle, tapered gradually to the base, the lowest pinnae only 2 cm long, dull, dark green, leathery, rachis scales linear, straw-colored, lamina with whitish to brown narrow scales on both sides.
Pinnae: 20 to 40 pair, oblong; pinnules short-stalked, eared near the rachis, adnate further out, the first upper pinnule the same size or only slightly larger than the next ; margins edges toothed, with slender spiny tips; veins free, forked, anadromic.
Sori: round, distinct and separate, in 1 row between midrib and margin, sparse, indusium: peltate, light brown, shriveling in maturity, central, sporangia: gray-brown to black, maturity: midsummer to later.
Culture Habitat: cool, moist, shaded places in boreal forests and northern deciduous woods; also rocky slopes and moist cliffs. Distribution: North America, Europe, Asia. Hardy to -35°C, USDA Zone 3.
Distinctive Characteristics Similar in many respects to P. aculeatum, but the very small pinnae at the base are distinctive. This is also a larger plant with more fronds, a softer, duller lamina
Aspidium braunii Spenner
Polystichum braunii subsp. purshii (Fernald) Calder & Roy L. Taylor
Polystichum braunii var. purshii Fernald
Dryopteris braunii (Spenner) Underwood
Polystichum braunii
Polystichum braunii. frond; pinna base, hair-like scales, marginal teeth.  Illustration from Scandinavian Ferns by Benjamin Øllgaard and Kirsten Tind, Rhodos, 1993.
Polystichum braunii
Polystichum braunii. Vascular bundles at base of stipe (below) and fewer at the top of the stipe. An example with 7 bundles at the base would be no surprise.  Drawing from Ferns of Northeastern United States, Farida A. Wiley, 1936.
Polystichum braunii
Polystichum braunii. a) frond, b) portion of fertile pinna, c) sorus.  Illustration by V. Fulford from Ferns and Fern Allies of Canada, William J. Cody and Donald M. Britton, 1989, © Agriculture Canada, used with permission.
Polystichum braunii
Polystichum braunii. Habit; stipe scales. Note tasseling during unfurling, typical of Polystichum.  Illustration from Scandinavian Ferns by Benjamin Øllgaard and Kirsten Tind, Rhodos, 1993.
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