HO IV TO KNOW THE WILD FLOWERS 



lower flowers are lengthened while those of the upper remain 

 shorter. 



A cluster in which the flower-stalks all spring from apparently 

 the same point, as in the Milkweeds, somewhat suggesting the 

 spreading ribs of an umbrella, is called an Umbel (PI. CXXIII.). 



A cluster which is formed of a number of small umbels, all of 

 the stalks of which start from apparently the same point, is called 

 a Compound Umbel. 



A close, circular flower-cluster, like that of Pink Clover or 

 Dandehon is called a Head. (Sunflower, PI. LXXIX.) 



A flower-cluster along the lengthened axis of which the 

 flowers are sessile or closely set is called a Spike. (Mullein, PI. 

 LXXIIL) 



A Spadix is a fleshy spike or head, with small and often im- 

 perfect flowers, as in the Jack-in-the-Pulpit, and Skunk Cabbage 

 (Pis. CLV. and CLIII. ; also Fig. 4). 



Fig. 4. 



Fig. 5. 



Fig. 6. 



A Spathe is the peculiar leaf-like bract which usually en- 

 velops a spadix. (See Jack-in-the-Pulpit and Skunk Cabbage, 

 Pl§, CLV. and CLIII. ; also Fig. 5.) 



A Bract is a leaf belonging to or subtending a flower-cluster 

 or a flower. It differs from the ordinary leaves usually in shape 

 or size, sometimes in texture and color. The flower of an orchid 

 is always subtended by a bract. (See Adder's Mouth, PI. 

 XCVII.) 



Involucre is the name given to the circle or spiral collection 

 of bracts around a flower-cluster. (See Wild Sunflower, PI. 



XXX 



