The Fern Lover's Companion / A Guide for the Northeastern States and Canada

by George Henry Tilton

[Illustration: Oak Fern. Phegopteris Dryopteris]

(2) THE NORTHERN OAK FERN

Phegopteris Robertiana. Phegopteris calcàrea

THELÝPTERIS ROBERTIÀNA

Resembles the oak fern, but with fronds rather larger, especially the terminal segment; also more rigid and coarser in appearance. Stalks and fronds minutely glandular beneath. Lower pinnules of the lateral divisions scarcely longer than the others. Often called "Limestone Polypody," the beech ferns having formerly been classed with the polypodies. Britton and Brown designate it as the "Scented Oak Fern." Canada and the northwestern states. Rare.

[Illustration: Northern Oak Fern. Phegopteris Robertiana (From Water's "Ferns," Henry Holt & Co.)]

[Illustration: BROAD BEECH FERN. Phegopteris hexagonoptera]