Herbaceous Plants 291 



ure. If well cut back when through flowering, it often 

 gives a second crop of flowers. R. Newmanii, the perennial 

 form of the Black-Eyed Susan, attains a height of 3 feet, 

 and the deep orange-yellow flowers with a dark purple 

 cone add variety to the flower border. R. purpurea (Giant 

 Purple Cone Flower) has peculiar reddish-purple flowers 



FIG. 1 66. Yucca filamentosa. 



with a large brown cone-shaped center, and blooms from 

 July to October. 



Sunflower (Helianthus). Many of the hardy sun- 

 flowers are useful perennial plants. The plants of some 

 species are tall, 5 to 12 feet, with large or very large 

 attractive yellow flowers. Some kinds spread too rapidly 

 to be desirable unless planted in a box or tub of soil. The 

 plants are easily propagated by division. Planted in masses, 

 sunflowers are very effective. Helianthus decapetalus, var. 

 multiflorus, and its garden varieties do not spread so rapidly 



