EXERCISES 187 



Hessian fly also attacks barleys, although it seems to prefer 

 wheat. The hessian fly may he quite injurious to winter barleys in 

 the Southern States. 



EXERCISES 



Barley differs from wheat and rye in having three flowers at a joirfc 

 of the rachis, and but one grain per spikelet. 



In the six-row barleys all three flowers are fertile and bear grains. 



In the two-row barleys the lateral flowers are sterile. 



It will be observed that the empty glumes are very narrow in barley, 

 while in wheat and oats they are broad, enclosing the flowers. 



Read carefully text and classification of barleys. 



Barley Types. 1. Materials. Have at hand samples of the four prin- 

 cipal barley types, as- described in Chapter XXIII, and, in addition, hullesa 

 barleys of both the awnless and hooded types. 



2. Lay out heads of the types in order. 



Lay brace of spikelets from each type just below the respective type. 



3. Compare hexastichon and vulgare. 



Are all three grains in a brace same size? 

 Are any of the grains twisted? 



Compare the shape of grain, and also the prominence of the two nerves 

 on back. 



Can you identify threshed samples of the two kinds? 



4. See if you can find marks for identifying the two-rowed types in 

 threshed grain. 



Can you tell the threshed grain of the two-rowed and six-rowed apart? 



5. Drawings. Make drawings (x3) as follows: 

 (a) Spikelet of each type on short section of rachis. 



(6) Side view (grooved side) of short section of each spike, 

 (c) Ventral view (crease side) of one grain or two-rowed barley, and 

 three grains from same brace of common six-row (vulgare). 



6. Dissect a spikelet of hulless and draw parts in relative position. 



7. Threshed grain of white hulless barley and macaroni wheat are 

 sometimes confused. Compare samples. 



8. Compare threshed oats and common barley. 



Can you remove hull as easily in one case as the other? 

 Which has higher per cent, of hull? 



Descriptive Terms for Barley 



A. Spike: 



1. Rows six, two. 



2. Type slender, compact. 



3. Cross-section 6 rank, 4 rank, 2 rank. 



4. Awns persistent, awns deciduous, awnless, hooded. 



B. Spikelet: 



5. Number fertile. 



6. Number sterile. 



7. Color. 



C. Grain: 



8. Glumes free, adhering. 



9. Color of kernel. 



10. Shape long, medium, short. 



11. Texture starchy, dull, vitreous. 



