6 10 BOTANY or CROP PLANTS 



endocarp. Seeds are usually abundant, ilat. and without 

 endosperm. 



Germination of Cucurbit Seeds. -The cotyle(K)ns are 

 epigean in all the common members of the Cucurbitaceie. 

 There are a few hypogean forms, such as MegarJiiza calif oniica 

 and Sicyospeyma gracUis. The first portion of the seedling to 

 appear above ground is the hypocotyl, which emerges as an 

 arch (Fig. 249). At the base of the hypocotyledonar\- arch, 

 there is developed a peculiar outgrowth known as the " prg.'^ 

 It is a natural part of the plant, and although it \arics some- 

 what in size in dilTerent cucurbits, it has been shown that 

 gra\ity has no direct effect in increasing peg de\el<)[)nient 

 or in determining its lateral placement on the hyi)()cotyl. 

 The peg serves to hold the seed coat while the hy[)oc()lyl 

 withdraws the cotyledons from the coat. It will be noticed 

 (Fig. 249) that one edge of the ^cc(.\ coat is caught against the 



Key to Principal Genera 



C(jrolla rotate or campanulate, five-parted to or almost to the base. 



Tendrils often two to three times branched, Cilrulliis (watermelon, citron). 



Tendrils simple, Cncumis (muskmelon, cantaloupe, cucumber). 

 Corolla campanulate,' fivc-lobed to or little below middle Ciicurhild (j,'ourd 



pumpkin, squash). 



CUCURBITA (Squash, Pumpkin, Gourd) 



Stems, Leaves, Flowers. — Members of this genus arc 

 annual, prostrate bushy or trailing vines with rough stems 

 which have a tendency to root at the nodes. The tendency is 

 particularly marked in the long-running varieties of scjuashes 

 (Turban, Marblehead, Canada Crookneck, Field Pumpkin). 

 The tendrils are branched. The leaves are usually cordate 

 at the base, lobed (C. pepo), or not Ujljcd iC. ffiaxinia). 

 The jlou'crs are alwa}'s solitary in the a.xils of the lca\es, 

 yellow, and monoecious. In squashes with a bushy habit 



