ORNAMENTAL PLANTS 



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disc flowers. Types with ray flowers in a wide range of tints 

 and, in the double varieties, lacking disc flowers entirely, have 

 been produced. Cosmos is a bushy garden flower from the same 

 region, with showy flower head made up of various colored ray 

 flowers and yellow disc flowers. The dahlia is another Mexican 

 plant which grows taller and more vigorously than most Com- 

 posites; the ray flowers are usually red or purple in color and in 



Fig. 305. — The Thistle Family has given man many beautiful garden flowers, 

 among them zinnia (A), cosmos (B), dahlia (G), and marigold (D). 



the original species the disc flowers are yellow. In many varieties 

 the disc flowers have been transformed into ray flowers. The 

 MARIGOLDS are another genus of tropical American plants, 

 typically with strongly scented foliage and a small flower head 

 of yellow or orange ray flowers and disc flowers. Most showy of 

 all the ornamental Composites is the chrysanthemum, a genus 

 cultivated in the Orient for the past thousand years. Ornamental 

 garden varieties number into the thousands, in many cases 

 double flowers resulting in huge spherical flower heads as in the 

 pompom types. 



