On the Marsilee of North America. 55 
Marsilee of North America. 
The North American Marsilee form a peculiar group, well 
distinguished from the species of the old world by the large pur- 
ple stomata of the capsule, which is always solitary at the base of 
the petiole, and by the two large conspicuous approximate teeth 
of the raphe. 
Marsilea uncinaia, A. Braun. (Fig. 1.) Fruit basilar and single; 
stipe erect, nearly twice the length of the capsule ; capsule hori- 
zontal, short oval or suborbicular, iderably p 1, truncate 
behind with along raphe which terminates in two approximate 
teeth, the upper one being the longest and uncinately recurved ; 
stomata of the capsule large, purple; pales appressed; 13 to 14 
sori on each side in the capsule ; leaflets narrow at base, fan- 
shaped, entire, nearly naked. 
Marsilea mucronata, A. Braun, MSS. (Fig. 2.) Fruit basilar 
and single ; stipe ascending, hardly as long as the capsule ; capsule 
nearly horizontal or slightly ascending, somewhat obliquely oval, 
slightly compressed, rounded above, carinate below, truncate be- 
hind, with a shorter raphe, which terminates in two approximate 
teeth, the upper one being the longest and straight or slightly 
curved at the point; stomata of the capsule large and purple; 
palez appressed, indistinct ; 8-to 9 sori on each side of the cap- 
sule ; leaflets spathulate, entire, slightly hairy. : 
Marsilea vestita, Hook. and Grev. (Fig. 3.) Fruit basilar and 
single ; stipe erect, hardly as long as the capsule; capsule ascending, 
oval, somewhat compressed, with a short raphe which terminates 
in two approximate teeth, the lower one being short and blunt, the 
Upper one acute, a little larger, hardly curved ; palez long, dense 
and somewhat patulous ; 7 to 8 sori on each side in the capsule ; 
leaflets entire, covered with paleaceous hairs. (Stomata of the 
capsule not seen in the young specimen examined by me, but 
undoubtedly similar to those of the other two species, only more 
hidden by the palee. ) 
Fig. 2. Fig.1. Fig. 3. (Half the natural size.) Fig. 4. 
This last species was the first of the genus discovered in North 
America. It was collected by Douglas on the Columbia river, 
