Sporangia naked, globular, pedicelled, reticulated, opening by a vertical slit.
16. Osmun'da. Fertile fronds or fertile portions of the frond much contracted, bearing naked sporangia, which are globular, short-pedicelled, and opening by a vertical slit to discharge the spores. Frond tall and upright, once- or twice-pinnate, from thick rootstocks.
Sporangia naked, not reticulated, opening by a horizontal slit. Fronds not circinate in the bud.
17. Botrych'ium. Sporangia in compound spikes, distinct, opening by a horizontal slit. Sterile part of the frond compound. Veins free. (See Figs. 270 and 271).
18. Ophioglos'sum. Sporangia coherent in 2 ranks on the edges of a simple spike. Sterile part of the frond simple. Veins reticulated.
P. Vlllga're, L. Fronds evergreen, 4-10 inches long, deeply pinnatifid, the lobes obtuse and obscurely toothed. Sori large. - Common on shady rocks.
A. pedatum, L. Stipe upright, black and shining. The frond forked at the top of the stipe, the two branches of the fork recurved, and each bearing on its inner side several slender spreading divisions, the latter with numerous thin pinnatifid pinnules which look like the halves of pinnules, owing to the midrib being close to the lower edge. Upper margin of the pinnules cleft. - Common in rich woods.
P. aquili'na, L. Stipe stout and erect. Frond large and divided into 3 large spreading divisions at the summit of the stipe, the branches twice-pinnate, the pinnules margined all round with the indusium. - Common in thickets and on dry hillsides.
1. P. gra'cilis, Hook. Fronds 3-6 inches high, slender, of few pinnae, the lower ones once- or twice-pinnatifid into 3-5 divisions, those of the fertile fronds narrower than those of the sterile ones. Stipe polished, brownish, darker at the base. - Shady limestone rocks; not common.
2. P. atrapurpu'rea, Link. Larger than the last, 6-15 inches high, the stipe dark-purple and shining. Frond pale, once- or (below) twice-pinnate, the divisions broadly linear or oblong (or the sterile sometimes oval), stalked at the base. Stipes clustered. - Dry rocks.
* Indusium straight, attached to the upper side of the vein.
1. A. Trichom'anes, L. A very delicate little fern growing in tufts on shaded cliffs. Fronds 3-6 inches long, linear in outline, pinnate, the little pinnae oval and unequal-sided, about 1/5 of an inch long. The stipes thread-like, purplish-brown and shining. This species is evergreen.
2. A. vir'ide, Hudson. Resembling A. Trichomanes, but less rigid, and the stipe brownish at base, becoming green upwards. Pinnae roundish-ovate or ovate-rhomboid, short-stalked, crenately toothed. - Shaded cliffs, Atl. Prov. chiefly.
3. A. ebe'neum, Ait. Evergreen. Fronds 9-18 inches high, upright, linear, oblanceolate in outline, fertile ones much the taller, simply pinnate. Pinnae mostly alternate, sessile, finely serrate, the base auricled on the upper or both sides. Stipe and rhachis blackish-purple and shining. - Rocky open woods, Ontario.
4. A. thelypteroi'des, Michx. Not evergreen. Fronds 2-3 feet high, pinnate, the pinnae linear-lanceolate in outline, 3-5 inches long, deeply pinnatifid, each of the crowded lobes bearing 3-6 pairs of oblong fruit-dots. - Rich woods.
5. A. angustifo'lium, Michx. Not evergreen. Fronds simply pinnate, somewhat resembling Aspidium acrosti-choides, but very smooth and thin, and larger. Pinnae cren-ulate, short-stalked. Fruit-dots linear, crowded. - Rich woods; not common.
* * Indusium curved, delicate, often crossing the vein, thus appearing reniform.
6. A. Filix-foe'mina, Bernh. Fronds 1-3 feet high, broadly lanceolate in outline, twice-pinnate, the pinnae lanceolate in outline, and the pinnules confluent by a narrow margin on the rhachis of the pinna, doubly serrate. Indusium curved, often shaped something like a horse-shoe, owing to its crossing the vein and becoming attached to both sides of it. - Rich woods.
Smith. Chain Fern. W. Virgin'ica, Smith. Fronds 2-3 feet high, pinnate; pinnae lanceolate, pinnatifid. Veins forming a single row of meshes next the midrib. - Wet swamps.
Smith. Hart's Tongue. S. vulga're, Smith. Frond simple, bright green, a foot or more in length, and an inch or more in width. - Shaded ravines and limestone cliffs; not very common.
Link. Walking-Leaf. C. rhizophyl'lus, Link. A curious little fern, growing in tufts on shaded limestone rocks. Frond simple, with a very long narrow point. - not very common.
Fee. Beech Fern. 1. P. polypodloi'des, Fee. Fronds triangular, longer than broad, 4-6 inches long, hairy on the veins, twice-pin-natifid, the rhachis winged. The pinnae sessile, linear-lanceolate in outline, the lowest pair deflexed and standing forwards. Fruit-dots small and all near the margin. Stipes rather longer than the fronds, from a slender, creeping rootstock. - Apparently not common, but growing in rich woods near Barrie, Ont.
2. P. hexagonop'tera, Fee. Fronds triangular, generally broader than long, 7-12 inches broad. Pinnae lanceolate; the lowest very large, their divisions elongated and pinnatifid, the basal divisions decurrent on the main rhachis and forming a many-angled wing. Fruit-dots not exclusively near the margin. - Rich woods.
3. P. Dryop'teris, Fee. Fronds broadly triangular in outline, primarily divided into 3 triangular spreading petioled divisions, smooth, the three divisions once-or twice-pinnate. Fronds from 4 to 6 inches wide. Fruit-dots near the margin. - Rich woods; common. Whole plant delicate, and light green in colour.
4. P. calca'rea, Fee. Closely resembling P. Dryopteris, but differs in the fronds being minutely glandular and somewhat rigid, and in the lowest pinnae on the lower side of the lateral divisions proportionally smaller. - Rocky hillsides, Restigouche River.