THE GRASS FAMILY. 137 



XIV. THE GRASS FAMILY. 



MATERIAL REQUIRED. 



Entire plants of cultivated wheat, soon after it has headed out. 



Similar specimens bf the following grasses : Chess, Bromus secalinus, L. ; 

 Quick-grass, Ayropyrum repens, Beauv. ; Orchard-grass, Dactylis 

 ylomerata, L. ; Fowl meadow-grass, Glyceria nervata, Trin.; Barn- 

 yard-grass, Panicum Crus-galli, L. ; Indian rice, Zizania aquatica, 

 L. ; Bur-grass, Cenchrus tribuloides, L. ; Beard-grass, Andropogon 

 furcatus, Muhl. ; Timothy, Plileum pratense, L. ; June grass, Poa 

 pratensis, L. 



Some of these can be obtained in a suitable condition for study early 

 in June in the northern States, and at a still earlier date farther 

 south ; others are best examined in late summer or autumn. Rye 

 may be used instead of wheat, and other substitutions may be 

 made if necessary. 



WHEAT. Triticum vulgare, Villars. 

 General Characters. 



I. Taking a number of entire and uninjured specimens, 

 determine first the relation of the stem and root system. 

 Is there anything to show whether more than one culm is 

 produced from a grain of wheat ? " By the process of til- 

 lering, or multiplication of stems from one root . . . over 

 fifteen hundred grains have been obtained from a single 

 seed." The beginnings of this process may be observed in 

 seedlings of wheat started in the laboratory. 



II. Examine the stem, culm, and note all peculiarities of 



1 The Graminese will be studied to better advantage after some other 

 families of monocotyledons, such, for example, as the Liliaceae, 



