l6 THE BOOK OF USEFUL PLANTS 



rowing, unless the seeding is done by a press drill, 

 that puts the grains underground at least an inch. 

 The harrow kills weeds, breaks up the surface 

 crust and covers the seed. The newest tool, the 

 press drill, does all these operations at once: seed- 

 ing, covering, and smoothing the bare ground over 

 the seed. 



If weather is fair an'd warm, the wheat field 

 shows its green spears at the end of the second 

 week after sowing. Soon the bare ground has 

 turned green as a lawn. One long leaf at each 

 joint of the stem is the rule with the wheat plant, 

 and that leaf in two sections : the lower half clasps 

 the stalk; the upper half extends outward, expos- 

 ing its flat surface to the sun. This is the part 

 that waves in the breezes. Many people would 

 overlook the tubular part that strengthens the 

 stalk, and only serves its leaf function by exposing 

 the green under surface to the sun. When wind 

 lashes the standing grain the leaves swing around 

 without breaking, because the basal half of each 

 is tough-fibred and takes a spiral twist around the 

 stem. This saves the leaves in many a storm from 

 being whipped off. 



The swollen joints, too, save the wheat that 

 gets "lodged" by wind. Strangely enough, the 

 swelling of the base of the leaf-sheath on the side 



