20 
FERNS OF THE Tf'EST. 
folded together and so half-moon-shaped, glaucous; involucre narrow, 
whitish, soon unrolled and exposing the spore-cases. Stalks dark-brown. 
Scales on the rootstock very narrow, upper half or two-thirds hair-like, 
often cleft. 6 to 12 inches high. 
Crevices of rocks. Sierras, California. 
51. P. flexuosa, Link. (The easi’ly bending P.) 
Fronds bi- or tri-pinnate; final divisions broadly ovate or heart- 
shaped, very obtuse ; involucre at length flattened out and exposing the 
spore-cases. Rachis and its branches bent in a zigzag way. Stalks red- * 
dish. 6 to 24 inches or more long. {Allosorus , Kaulfuss; P. inter- 
media, Kuhn.) 
Texas to Arizona; south to Peru. 
- VI. CB-TPTOGPAMME, R. Brown. RocK-feRAKE. 
Fruit-dots round or oblong, soon running together. Fronds smooth; 
the sterile ones with ovate or obovate toothed or cut divisions, tri- to 
quadri-pinnate ; fertile ones taller than the sterile, long-stalked, less 
divided; the divisions linear or oblong-linear, pod-like. Occasionally 
the upper part of the fertile frond is sterile. (Greek iox hidden-spore si) 
A genus of two species, one American and one European. 
52. C. acrosticRoides, R. Brown. (The Acrostichum-like C.) 
Sterile fronds leathery, dark-green, scalloped or toothed; fertile 
yellowish and thinner. (A/iosorus , Sprengel.) 
In dense tufts among rocks, California to Colorado and Lake Superior; north to 
latitude 56° or 60°. It has been found growing above timber line (12,000 feet above the 
sea) in Colorado. 
VII. PTEE-IS, Linnaeus. Brake. Bracken. 
Fronds in our species large; veins free. (Greek wmg, because the 
fronds are pinnate, feather-like.) 
A large genus, chiefly tropical, A very few species in the southern States. 
53. P. aqilililia, Linnaeus. (The P. iihe an eagle' s beak.) 
Frond 2 to 3 feet long and broad, almost leathery, smooth in the 
typical form, bi- to quadri-pinnate at base; lowest pinnae rather long- 
stalked; pinnules oblong-lanceolate or linear-halberd-shaped, entire or 
pinnately parted: final divisions oblong or linear, obtuse; terminal ones 
rather long, tapering; veins much forked. Stalks solitary, erect, light- 
colored, naked, swollen at base. Rootstock large, thick, having the 
partly decayed woody remains of the stalks of previous seasons. 
Thi'oughout the United States; less common westward. Various parts of the world. 
In wet or damp places. Young fronds and rootstocks often used for food. 
54. Variety IjllliigillOSa, Bong. (The woolly variety.) 
Lower side of fronds silky or woolly; final divisions broad. 
Common in California, east to Colorado. Merely a western form of the species. 
Very often grows on dry hillsides, and is six feet high. 
