CYPERACEAE 



175 



Lower spikes not radical; scales not 



abruptly cuspidate. 18. Albae. 



Bracts with well developed blades. 



Pistillate spikes short oblong to linear, 

 erect, or if drooping the spikes 

 short and the perigynia acutely 

 triangular. 

 Achenes lenticular; styles two. 19. Bicolores. 



Achenes triangular; styles three. 

 Perigynia with few to many strong 

 nerves or nerveless. 

 Perigynia tapering at base, 

 triangular, closely en- 

 veloping achene. 

 Rootstocks long creeping. 

 Rootstocks not long creep- 

 ing. 

 Perigynia rounded at base, 

 suborbicular in cross sec- 

 tion, loosely enveloping the 

 achene. 

 Perigynia finely many-striate. 

 Perigynia tapering at base, 



constricted at apex. 

 Perigynia rounded at both 

 ends. 

 Pistillate spikes elongated, linear to 

 cylindric, slender-peduncled, the 

 lower drooping. 

 Perigynia beakless or short beaked; 



terminal spike gynaecandrous. 

 Perigynia conspicuously or strongly 

 beaked. 

 Culms strongly reddish tinged at 

 base, aphyllopodic. 

 Leaves glabrous; spikes very 



slender. 

 Leaves pubescent; spikes 

 dense. 

 Culms not reddish tinged at 

 base, phyllopodic. 

 B. Lowest bract sheathless to strongly green- 

 sheathing; if green-sheathing achenes len- 

 ticular and perigynia not dull and sub- 

 terete, or perigyniawith strongly bidentate 

 non-hyaline apex and stiff teeth. 

 Perigynia or foliage (at least the lower 

 sheaths) pubescent; perigynia beak- 

 less or the beak not strongly biden- 

 tate; achenes triangular. 

 Terminal spike gynaecandrous. 29. Virescentes. 



20. Paniceae. 



21. Laxiflorae. 



22. granulares. 



23. Oligocarpae. 



24. Griseae. 



25. Gracillimae. 



26. Debiles. 



27. Flexiles. 



28. longirostres. 



