CLASSIFICATION OF FERNS. 
105 
2. L. annotinum . Leaves indistinctly 5 -rowed, linear- 
lanceolate ; spikes solitary, sessile. 
3. L . inundatum. Leaves scattered, curved upwards, 
linear; spikes solitary, sessile. 
4. L. selaginoides. Leaves scattered, half-spreading, 
lanceolate ; spikes solitary, sessile. 
5. L . alpinum. Leaves in four rows, pressed close to 
the stem ; spikes solitary, sessile. 
6. L . Selago. Leaves in eight rows, overlapping one 
another on the erect, bushy stems ; fructifica- 
tion in the axils of the leaves, not in spikes. 
MARSILEACEiE. 
19. Isoetes. 
1. I. lacustris. Leaves erect, bristle-shaped, cellular; 
* fructification in the base of the leaves. 
2. /. Durimi. Leaves slender, spreading. 
20. PlLULARIA. 
1. P. glohulifera. Leaves slender, rush-like, cylindrical ; 
capsule stalked. 
/ 
EQTJISETACEiE. 
21. Equisetum. 
1. E. Telmateja. Sterile stems branched, smooth, with 
about thirty ridges ; fertile ones simple, short, 
with large crowded sheaths, and awl-shaped 2- 
ribbed teeth. 
2. E. umbrosum. Sterile stems branched, rough, with 
about twenty ridges ; fertile ones simple, with 
close-fitting sheaths, having awl-shaped 1-ribbed 
teeth. 
