454 THE CAMPANULALES 



Here belong the goat's beard (Adopogon), hawkbit (Leontodon), 

 sow thistle (Sonchus), hawkweed (Hieracium), rattlesnake root 

 (Nabalus), as well as several introduced and native plants that 

 are cultivated, as the dandelion (Taraxacum), species of chicory 

 (Cichorium), salsify (Tragopogon) , lettuce (Lactuca). The 

 character of the head, flower and fruit of this family are well 

 shown in the dandelion (Fig. 339). All the flowers are ligulate, 



FIG. 339. Flowers and fruit of Taraxacum: A, sectional view of in- 

 florescence in, involucre. The flowers in the center of the head not as 

 yet in bloom. B, an unopened flower. The thread-like calyx (pappus) 

 and corolla arising from the ovary, o. C, corolla opening. D, later stage, 

 the style has elongated, sweeping the spores from the sheath of anthers, 

 an, and the two stigmatic lobes are beginning to open. E, flower in full 

 bloom, the stigma lobes recurving. F, mature fruit. The pappus is lifted 

 up on a long, slender outgrowth of the ovary, o. 



the five lobes frequently to be seen on the margin of the corolla 

 indicating the number of petals, and the calyx assumes the form 

 of minute hairs (Fig. 339, B-E). The five filaments adhere to 

 the tube of the corolla while the anthers form a cylinder about 

 the style and discharge their spores before the flower opens. The 

 style begins to elongate as soon as the flower opens and pushes 



