36 



THE INDIANA WEED BOOK. 



elongated and pointed. In the calyx of many weeds the sepals 

 are wholly separate and distinct one from another. In the different 

 weeds they also vary greatly in shape, size and degree of union, so 

 that the calyx may be shaped like a cup, bell, saucer, urn, tube and 

 many other objects. In some weeds the calyx is colored like the 

 corolla while in some it is wholly lacking. However, if but one 

 set of floral envelopes is present it is the calyx, whatever its color, 

 and the flower is said to be apetalous; while if both calyx and 

 corolla are absent the flower is naked. 



The inner floral envelope when present is called the corolla. 

 It is also made up of several leaf-like parts arranged in a whorl 

 or circle and called petals. The petals are usually brightly colored 

 and larger than the sepals. They also vary greatly in the different 

 weeds in number, form, size, color and degree of union one with 



Fig. 10. Illustrating forms of corollas: a, polypetalous flower of bouncing bet showing the 5 petals with lorg 

 claws or stalk-like bases; b, gamopetaloas bell-shaped corolla of bell-flower; c, salver-shaped corolla of phlox; 

 d, wheel-shaped corolla of nightshade; e.same of potato, the lobes less divided; f, funnel-form corolla of morning- 

 glory; g, strap-shaped corolla of a Composite. (After Gray.) 



another. In the corn cockle the petals are 5, purple-red, separate, 

 broader and slightly notched above and narrowed into wedge-like 

 claws below. When the petals are wholly distinct one from another 

 the corolla is said to be polypetalous; when more or less united, 

 gamopetalous. If the petals are all alike, as in the cockle, the 

 corolla is regular; if one or more of them differ in size or shape 

 as they do' in many weeds, especially those of the pea and mint 

 families, the corolla is irregular. 



The form of the corolla varies much and, like that of the calyx, 

 is often described as being bell-, funnel-, wheel-, tube-, or other- 

 wise shaped. In the weeds of the bell-flower, mint and figwort 

 families the corolla is more or less two-lipped, the petals being so 

 united that two of them form an upper or overhanging portion, 

 while the other three form the lower lip. In the dandelion, ox-eye 

 daisy, dog-fennel and other weeds of the Chicory and Composite 



