370 



PEACTICAL BOTANY 



these are bachelor's-button, China aster, chrysanthemum (in- 

 cluding feverfew and marguerite), coreopsis, cosmos, dahlia, 

 English daisy, everlastings, marigold, sunflower, zinnia. 



340. Useful plants of other families. Several plants belonging 

 to families of sympetalous dicotyledons not already described 

 are important enough to be 

 briefly mentioned. 



The Olive family ( Oleacece) 

 furnishes two ornamental 

 shrubs, lilac and forsythia, 

 and an important genus of 



D 



FIG. 304. Akenes with various types of pappus 



A, Rudbeckia, pappus wanting ; B, Cichorium, pappus a crown of fine scales ; (7, 

 Coreopsis, pappus of two small scales ; D, Helenium, pappus a crown of conspicu- 

 ous scales ; E, Cirsium, pappus a tuft of plumose hairs ; F, Lactuca, pappus borne 



on a long beak 



timber trees, the ash genus. The olive itself is probably a 

 native of the eastern Mediterranean region. It is now con- 

 siderably grown in California. 



The G-ourd family (Cucurlitacece) furnishes many edible 

 fruits. Of these the pumpkin and the summer squashes are varie- 

 ties of the same species and the large winter squashes belong 

 to another species of the same genus (Cucurbita), probably of 

 American origin. The watermelon belongs to a genus ( Citrul- 

 lus) of Asiatic origin. The muskmelons, cantaloupes, nutmeg 

 melons, and the cucumber belong to a third genus ( Cucumis) 

 and are modified forms of two southern Asiatic species. 



The Morning-glory family (Convolvulacece) contains one 

 highly useful food plant, the sweet potato, which belongs to 

 the same genus (Ipomoea) with some of the morning-glories. 



