
CRYPTOGAMIA, FILICES. 213 
Maiden-hair. Mow-hair. 
With the exception of Botrychium Virginicum, this is the 
most elegant fern in our neighbourhood. From one to two 
feet high. Stem dark, smooth, and shining. In rich shady 
woods; very common. Possesses medicinal virtues? Peren- 
nial. July. 
397. DICKSONIA. L’Herit. sert. angl. 30. 
Sori punctiform, marginal, subrotund, dis- 
tinct. Indusium double, alternate, superfi- 
cial, exterior gaping, the other marginal 
gaping within.— Nutt. 
1. D. fronds bi-pinnate; pinnule oblong-lanceo- pilosiuscula, 
late, pinnatifid, upper margin of the segments 
incised-dentate ; rachis somewhat hairy.— Willd. 
D. pubescens, Schk. 
Polypodium pilosiusculum, Muhl. in litt. 
Hairy Dicksonia. Small-fruited Dicksonia. 
From twelve to fifteen inches high. In shady woods, and 
particularly on rocks; common. Perennial. July. 
398. ISOETES. Gen. pl. 1620. 
Capsule membranaceous, not gaping; frond 
immersed at the base, 1-locular. Seed an- 
gular, inserted into the numerous filiform 
receptacles.— Nutt. | 
1.1. frond subulate, semi-terete.— Willd. lacusttis. 
Icon. Schk. filic. t. 173. Fl. Dan. 191. Dill. 
mus. t. 80. f. 1. 
From one to two inches high. In a boggy wood south of 
Laundreth’s Gardens, and on the overflowed shores of the 
Delaware, above Kensington; very abundant, Perennial, July. 
19* 
