FERNS AND FERN-AEEIES 
323 
1. P. Dryopt^ris Oak fern 
Lvs. 1-1. 5dm/ long and wide, of 3 nearly equal 1-2-pinnate 
parts ; stalk slender, l-3dm. tall, chaffy at base. 
In rich rocky woods ; very rare here. 
Eldora. 
Nfd. to Oreg. and Alaska; also Eurasia. 
July. 
Note: P. hexagonoptera is reported from Steamboat Rock. 
3. A diant um Maidenhair 
(A, without; diainein, to be wetted; the If Its. shed water) 
Lvs. very thin, on slender, shiny, black stalks. Sporangia in 
groups on margin of If It., covered by the turned back margin of 
the Iflt. 
1. A. pedatum Bird-foot A. Common M. 
Leaf standing horizontally on top of a stalk which is 2-4dm. 
tall; stalk forking at summit, bearing the If Its. on one side of 
each fork. 
• Lower margin of Iflt. smooth, the veins all coming from this 
edge; sori on opposite margin. 
Rich woods, frequent. 
Moore; Sugar Creek. 
Ga. to Cal., N. S., and Alaska; also in Asia. 
July. 
4. Pteridium Bracken fern 
(Pteris, the ancient Greek name for ferps; from pteron, a wing, the lvs. being 
usually pinnate) 
Lflts. firm, l-2cm. long, the margins turned back all round to 
cover the sporangia. Lf. 6-10dm. tall, 3-6dm. wide, broadly tri- 
angular, at right angles to stalk. 
Rhizome 5- 10mm. thick, several meters long, black, with 2 
bands of black fibrous tissue inside. 
1. P. aquilinum Eagle fern 
Characters of the genus. 
Dry wooded hills, rare here. 
3 miles west of Tama ; Eldora. 
World wide in range. 
July- Aug. 
Note: The rhizomes of this fern furnish edible starch to the aborigines 
in our northwest, in New Zealand, and elsewhere. The leafstalk is re- 
markable for having 2 deep nectar glands at the top. 
