60 



CYPEEACEAE. 



Perigynia shorter, usually spreading at maturity, thin- 

 margined. 

 Perigynia little exceeding the scales : entirely staminate 



spikes numerous. 

 Perigynia much exceeding the scales : entirely staminate 

 spikes normally absent. 



Perigynia beak 1/5-^4 the length of the scarcely ser- 

 rulate body, the teeth very short, the suture on 

 inner side inconspicuous : scales very obtuse to 

 acutish. 

 Perigynia beak % to nearly the length of the 

 strongly serrulate body, strongly bidentate, the 

 suture conspicuous : scales often sharper. 

 Perigynium-body lanceolate to broadly ovate, 

 narrowed into a beak more than half its 

 length, inconspicuously nerved on inner face. 

 Perigynium-body suborbicular, abruptly con- 

 tracted into a beak less than half its length, 

 conspicuously nerved on inner face. 



VI. OVALES. 



Perigynia narrowly to broadly lanceolate, at least 2 V> times 

 as long as wide. 

 Leaf-blades at most 3 mm. wide, those of sterile shoots 



few, ascending. 

 Leaf-blades broader, those of sterile shoots numerous, 

 widely spreading. 

 Tips of perigynia appressed or ascending : spikes 



7-12 mm. long. 

 Tips of perigynia widely spreading or recurved : 

 spikes 4-8 mm. long. 

 Perigynia ovate-lanceolate or broader, at most twice as long 

 as wide. 

 Perigynia strongly exceeding the scales. 



Perigynia narrowly to broadly ovate, 3-4 mm. long. 

 Perigynia ovate to reniform, 4 mm. or more long. 

 Spikes approximate or scattered, the head stiff : 



scales obtuse or acutish. 

 Spikes in a moniliform flexuous head : scales 

 long-pointed. 

 Perigynia equalled by the scales. 



VII. Phtllostachyae. 



Body of perigynium oblong : pistillate flowers usually 3-10. 

 Body of perigynium globose : pistillate flowers usually 2-3. 



VIII. POLYTRICHOIDEAE. 



A single species in our range. 



IX. MONTANAE. 



None of the culms short and hidden among the bases of the 

 leaves. 

 Lower leaves reduced to sheaths : lower sheaths but 



little flbrillose : plants not stoloniferous. 

 Lower leaves blade-bearing : lower sheaths usually 

 strongly flbrillose : plants stoloniferous. 

 Plants long-stoloniferous : staminate spike 12-24 



mm. long. 

 Plants little stoloniferous : staminate spikes 4-12 

 mm. long. 

 Many of the culms short and hidden among the bases of 

 the leaves. 



A single species in our range. 



X. Teiqueteae. 



XI. Peduncdi.atae. 



A single species in our range. 



11. C. stcrilis. 



12. C. interior. 



13. C. Leersii. 



14. C. incomperta. 



15. C. scoparia. 



16. C. trihuloides. 



17. C. cristatella. 



18. C straminea. 



19. O. festvcacea. 



20. C. Tiormathodes. 



21. C. foetiea. 



22. C. Willdenovii. 



23. C Jamesii. 



24. C. leptalea. 



25. 0. communis. 



26. C. pennsylvanica. 



27. C. varia. 



28. C. umhellata. 



29. C. hirtifolia. 



30. C pedunculata. 



XII. Paniceae. 



Perigynium-beak none or very short, often bent. 



Fertile culm-blades 6-10, 3-7 mm. wide : perigynia more 



