EXPLANATION OF PLATE VI. 



CAKEX. (1) C. trisperma, upper part of a stem in fruit; (2) enlarged 

 spike displayed, with three staminate and two pistillate flowers; (3) a 

 scale, and (4) a ripe perigynium, of the latter ; with (5) a section of the 

 perigynium near the base, and of the contained achene. (6) C. straminea, 

 var. brevior, summit of a fruiting plant; (7) a spike enlarged ; (8) scale 

 of a pistillate flower; (9) the winged perigynium and the contained 

 achene cut across; (10) detached achene with persistent style and stig- 

 mas. (11) C. umbellata, whole plant; (12) a perigynium and its scale; 



(13) cross-section toward the base of perigynium and its contained achene ; 



(14) detached achene with its persistent style and stigmas. C. bullata; 



(15) upper part of plant in fruit, with one pistillate and two staminate 

 spikes; (16) one of its staminate flowers with the scale ; (17) a pistillate 

 scale, and (18) mature perigynium; (19) longitudinal section of the lat- 

 ter, showing the achene and its style, and (20) cross section of the same. 



