FERTILE AND STERILE FRONDS LEAF-LIKE
Boott's Shield Fern is found in moist woods and near ponds. It is distinguished by its long, narrow fronds and minutely glandular indusium.
42. CRESTED SHIELD FERN
Aspidium cristatum (Dryopteris cristata)
Newfoundland to Kentucky, in swamps. One to more than three feet high, with stalks which are chaffy, especially below, and which have light-brown scales, stalks of sterile fronds much shorter than those of fertile fronds.
Fronds.—Linear-oblong or lance-shaped, nearly twice-pinnate, fertile ones taller and longer stalked than the sterile; pinnæ (of the fertile frond, turning their faces toward the apex of the frond) rather short, lance-shaped or triangular-oblong, deeply impressed with veins, cut deeply into oblong, obtuse, finely toothed divisions; fruit-dots large, round, half-way between midvein and margin; indusium large, flat.
In wet woods, growing either from the ground or from the trunks of fallen trees, and also in open meadows, we notice the tall, slender, dark-green, somewhat lustrous fronds of the Crested Shield Fern, usually distinguished easily from its kinsmen by the noticeably upward-turning pinnæ of the fertile fronds, and by the deep impression made by the veins on their upper surfaces.
The sterile fronds are much shorter than the fertile ones. They are evergreen, lasting through the winter after the fertile fronds have perished.
Near the Crested Shield Fern we find often many of its kinsmen, broad, feathery fronds of the Spinulose Wood Fern, more slender ones of Boott's Shield