[Chap. LI SOME FAMILIES OF FLOWERING PLANTS 717 



The gourd family ( Cucurhitaceae ) . The cucurbits are largely tropical 

 and subtropical, and are represented by about 100 genera and 800 

 species. Thev are herbaceous vines, generally tendril-bearing, succulent, 

 and often hollow-stemmed. Common examples are pumpkin, squash, 

 gourd, cucumber, cantaloupe, watermelon, and balsam apple. Gourds 

 have been used for centuries as receptacles for water and foods. The 

 cucumbers, melons, squashes, and pumpkins are valued for their flavors, 

 their vitamin content, and their use in pies and preserves. 



The sunflower family ( Compositae ) . The sunflower familv, including 

 the ragweed and chicorv groups, is the largest among flowering plants, 

 numbering nearlv 1000 genera and 20,000 species. Species of this famib 

 are found nearlv everywhere that land plants grow. They are mostly 

 herbs, though a few tropical species are shrubs and trees. The flowers 

 are generallv small with tubular or strap-shaped corollas, and are ar- 

 ranged in heads surrounded by circles of green bracts. The fruit is gen- 

 erallv an akene without an endosperm. Structuralh the plants are the 

 most specialized of dicots. 



A few species of the family are valued as food (sunflower, artichoke, 

 lettuce, salsify, and dandelion); and as ornamentals (dahlia, aster, 

 chrysanthemum, daisy). Some are the causes of hav fever (sagebrush 

 and ragweed), and others are poisonous to livestock (white snakeroot, 

 the cause of trembles and milk sickness ) . Many of them are extremely 

 troublesome weeds in pastures and areas under cultivation (cocklebur, 

 Canada thistle, ragweed, varrow, Spanish needle, dandelion, ironweed ) . 



REFERENCES 



Castetter, E. F., and W. H. Bell. Ethnobiological studies in the American 

 Southwest. IV. The aboriginal utilization of the tall cacti in the American 

 Southwest. Univ. of Neiv Mexico Bull. No. 307. 1937. 



Geske, E. J., and W. J. Showalter. Familiar grasses and their Howers. National 

 Geog. Mag. 39:625-636. 1921. 



House, H. D. Wild Flowers. The Macniillan Companv. 1934. 



Hylander, C. J. The World of Plant Life. The Macmillan Company. Part 4. 

 1939. 



Pool, R. J. Flowers and Floivering Plants. McGraw-Hill Book Company, Inc. 

 1929. 



Sargent, F. L. Plants and Their Uses. Henry Holt & Company, Inc. 1913. 



Saunders, C. F. Useful Wild Plants of the United States and Canada. Robert 

 M. McBride & Company. 1934. 



