Order 70.— ASTERWORTS. 



231 



ant, when all the florets areligiilate (Fig. 504) ; discoid., when all the florets 

 are tubular, there being no rays (Fig. 509). The receptacle is the broad 

 top of the stalk on which the florets sit (Fig. 499). It is chaffy when there 

 are scales or bracts growing among the florets, and naked when none. 



The tubular florets constitute the disk, and the ligulate, if any, the ray ; 

 the disk is generally yellow, while the ray is about as often cyanic (that is, 

 blue, red, white, or any color except yellow) as yellow. 



Fig 408. A Sunflower,— head radiate. 9. Vertical secition of the head, showing the scales of 

 the involucre, and a sinde disk-flower remaining u[»on the convex receptacle. Fig. 5u0. A per- 

 fect di^k-flnwer magnified, showing the achenium, the 2 awns of the pappus, the 5-to()thed tu- 

 bular corolla, the 5 stamens united around tiie bmnclied style, and the chaflF-scale at base. 1. Head 

 (ladiatc) of Solidago csesia, 2. A pistillate, ligulate flower of the ray. 3. A perfect disk-flower. 

 4 A (nidiaiit) head of Dandelion. 5. A perfect, ligulate flower. G. Achenium, with its Ions 

 beak and feathery pappus. 7. A (radiant.) head of Nabalus altissimus. S. A flower. 9 L 'ppn 

 (Burd ck), head discoid. 10. A flower. 11. One of the hooked scales. 12. A (di.-<coid) head <if 

 Enpatorium purpureum. Vi. A flower. 14 Ambrosia (Pigweed). 15. Staminato head enlarged. 

 16. Pistlllat ■ iavolucre enlarged. 17. The fertile flower. 



