538 



BOTANY OF CROP PLANTS 



priniar}- ril)sarL' Ihrcad-likc, while the lateral ribs are expanded 

 into broad. Hat wings, with those of the two mcricarps con- 

 tiguous. 'I'he oil tubes are solitary in the intervals; there 

 are iour on the dorsal side and two to four on the commissural 

 side. The olive-green seeds are llattened dorsally. The 

 seeds are very short-lived. 



Geographical. — The wild parsnip, Paslinaca saliva, from which our ciilti- 

 valcd variolics arc derived, is a native of Europe. This wild form has l)c- 

 comc naturalized in many sections of Xortli America, occurring as a weed 

 along roadsides and in waste places. 



Varieties.- — There are comparatively few parsnip \arieties. 

 rrobabl\' the most popular sorts are the Guernsey and Hollow 

 Crown. Tn both of these, the crown is concave. 



Fi.;. 



■Celery (Apium graveolens). A, schizocarp, external, X 15; B. 

 diagrammatic cross-section of scliizocarp, X 20. 



APIUM (Celery and Parsley) 



Generic Description.— Members of this genus are annual 

 or perennial herbs with pinnately dixided leaves. The white 

 or gveenish flowers are in compound umbels. The involucre 

 and involucels ma\' be present or wanting. The cal}x teeth 



