ORDER 70. ASTEHWORTS. 



231 



ant, when all the florets are ligulate (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, 

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



Fig 4 -S. A Sunflower, head radiate. 9. Vertical secition of the head', showing the scales o 

 the involucre, and a single disk-flower remaining upon the convex receptacle. Fig. 500. A per- 

 fect dit-k-fl iwer magnified, showing the acbenium, the 2 awns of the pappus, the 5-toothed tu 

 bular corolla, the 5 stamens united around the branched style, and the chaff-scale at base. 1. Heai 

 (/adiate) of Solidago csesia. 2. A pistillate, ll-rulate flower of the ray. 8. A perfect disk-flower 

 4 A (radiant) head of Dandelion. 5. A perfect, lignlate flower. 6. Achenium, with its Ions; 

 beak and feathery pappus. 7. A (radiant) head of Nabalns altissimu*. 8. A flower. 9. L'lppn 

 (Burd ck), head discoid. 10. A flower. 11. One of the hooked scales. 12. A (discoid) head of 

 Eupatorium purpureum. 13. A flower. 14. Ambrosia (Pigweed). 15. Staminate head enlarged. 

 16. Ptstillat involucre enlarged. 17. The fertile flower. 



