_Phegópteris dryópteris_. THELÝPTERIS DRYÓPTERIS
Fronds glabrous, broadly triangular, ternate, four to seven inches broad, the divisions widely spreading, each division pinnate at the base. Segments oblong, obtuse, entire or toothed. Fruit-dots near the margin. Rootstock slender and creeping from which fronds are produced all summer, in appearance like the small, ternate divisions of the bracken.
This dainty fern has fronds of a delicate yellow-green, "the greenest of all green things growing." Its ternate character is shown even in the uncoiling of the fronds, the three round balls suggesting the sign of the pawnbroker. The parts of the oak fern develop with great regularity, each pinna, pinnule and lobe having another exactly opposite to it nearly always. In rocky woods, common northward; also in Virginia, Kansas and Colorado. A fine species for cultivation at the base of the artificial rockery.
[Illustration: Oak Fern. _Phegopteris Dryopteris_]
_Phegopteris Robertiana. Phegopteris calcàrea_
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]
Fronds triangular, broader than long, seven to twelve inches broad, spreading more or less horizontally at the summit of the stipe; pubescent and often glandular beneath; pinnæ fragrant, lanceolate, the lowest pair usually much larger than those above, having the segments elongated and cut into lobes. Basal segments decurrent and forming a many-angled wing along the main rachis. Fruit-dots small, near the margin.
The broad beech fern is usually larger than its sister, the long beech fern, and extends farther south, ranging from New England to Minnesota and southward to Florida. It is sometimes called "six-angled polypody." According to Dodge it is most common in Rhode Island and Connecticut. It prefers rather dry, open woods. It is said to have a pleasant, ferny odor when bruised. August.