The Flower. 



97 



Fig. 50. Cross-section of flower-head of sun- 

 flower, Hclianthus annuun. Reduced. The flor- 

 ets appear closely crowded in the center of the 

 head. 



familiar example of a composite flower. One of the 

 separate flowers is shown in Fig. 51. At the outer edge 



of the flower-head, 

 is a row of individ- 

 ual flowers, each of 

 which has a long, 

 yellow, petal-like 

 appendage (Fig. 

 52), called a ray. 

 The flowers bearing 

 rays are called ray- 

 flowers. Some com- 

 posite flowers a s 

 the tansy* are with- 

 out ray-flowers. 

 149. The Flowers of the Grass Family f to which the 

 cereals belong, as well as corn, sorghum, sugar cane etc. , 

 are quite different from those of most other plants. In 

 this family, the flowers are arranged in little groups, 

 each of which is called a spike- 

 let. What we call a head of 

 wheat is made up of a number 

 of spikelets, one of which is 

 shown in Fig. 53. Fig. 54 

 shows the spikelet dissected. 

 The two scale-like parts at the 

 base, g. g., are called glumes. 

 The similar pair above, tipped 

 with a bristle (the awn or 

 beard) are called the lower or outer pales or palets (pa'- 

 lets) or flowering glumes — to distinguish them from the 



* Tanacetum vulgare. 

 t Graminece. 



Fig. 51 

 Fig. 51, 

 flower. 

 Fig. 52. Ray-flower of same, 



Fig. 52. 

 Enlarged floret of sun- 



