WILLIAMS: CALYMPERACEAE OF NorTH 
below the ee leaf-cells with often high, 
spine-like papil 
Leaves with point Enna to invurved: or 
nearly straight when dry and from two 
to many times longer than the basal part, 
or without a distinctly broader basal part. 
Costa’ without accessory guide-cells; stems’ 
usually much longer than the longest 
' leaves (about 12 mm 
Leaves rather distant with the point-abruptly 
spreading from the conspicuous, appressed 
base; costa dentate at apex, not papillose 
below. 
Leaves closer together on the stem with less 
spreading points; costa mostly papillose on 
the back in the upper part as well as den- 
Costa with accessory guide-cells; stems much 
shorter than the longést leaves (stems usually 
- 5-6 mm. long and leaves up to 4 cm. long). | 
Margin serrulate to enlarged base, or base with more 
or less serrate or eee border. 
Cells of leaf s 
Cells of leaf ae mamillose or papillose, that is, 
similar on both sides 
Costa about 25 wide halfway up; smooth 
except near the ape 
Costa 50 uw wide or more half way up. 
Smooth or with.minute, distant teeth on the 
back, the upper face papillose mostly from 
just above the cancellinae half way to 
apex. 
Rough with prominent, often spine-like 
teeth on the 
Costa spiny-dentate on the back in the 
upper half, otherwise smooth. 
Costa with dense, compound or forking 
papillae extending to below the can- 
celinae on the bac 
Border mostly wanting in upper third of leaf or in some 
leaves scarcely present or entirely wanting through- 
out. 
Cancellinae mostly broad and somewhat rounded 
e 
Cancellinae terminating above in narrowly acute angles 
next the costa 
Costa near the apex of cancellinae 60-80 uw wide and 
leaf-blade 0.6-1 mm. or more wide 
Costa near apex of cancellinae 40-50 wide and 
leaf-blade 0.25—0.50 mm. wide. 
AMERICA: 369 
8. 'S. inflexus. 
9. S. Husnoti. 
10. S. flavescens. 
11. S. tenuifolius. 
12. S. lycopodioides. 
13. S. recurvulus. 
14. S. graminicola. 
15. S. elongatus. 
16. S. texanus. 
17. S. ligulatus. 
18. S. parasiticus. 
19. S. filigerus. 
