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]
(3) BROAD BEECH FERN
_Phegopteris hexagonóptera_