EXERCISE XXVI. 

 THE OAT PLANT. 



Supplies for a Laboratory Section of Twelve. Twelve 

 oat plants; twelve wheat plants; twelve panicles of some 

 common oat ; twelve side oat panicles ; twelve wild oat 

 panicles; twelve two-ounce samples of each of the follow- 

 ing : Kherson. Swedish Select, and Texas Red. 



Part A. Characteristics of the Stems, 

 Leaves and Roots. 



1. Describe (a) the stem of the oat plant; 

 (b) the leaves; (c) the root system. 



2. Compare (a) the width of oat leaves with 

 the width of wheat leaves; (b) the leanness of 

 the oat plant with the leanness of the wheat plant. 



3. To what family of plants does the oat 

 belong? 



4. (a) Would you infer oat straw to be more 

 or less palatable than wheat straw? (b) Explain. 



Part B. The Oat Panicle. 



5. The flowering region or inflorescence of 

 the oat plant is known as a panicle. Fig. S3, page 

 86, illustrates the inflorescence of the oat plant. 

 Observe the main axis or rachis of the oat panicle 

 with which you are provided, (a) Do you find 

 it made up of nodes and internodes similar to 

 those of the stem? (b) From what points along 

 the main axis do branches arise? (c) Do these 

 branches have nodes and internodes? (d) Do 

 the branches themselves again branch? 



6. The oat spikelet is borne at the end of a 

 small flexible branch called a pedicel, (a) What 

 changes would be necessary in order to cause a 

 panicle to appear more like a spike? (b) What 

 parts of the spike correspond to the nodes and 

 internodes of the main axis of the oat panicle? 



7. (a) Draw the rachis of a spreading oat 

 panicle. The drawing should show accurately 

 the origin, position and direction of the branches 

 with reference to the rachis. Excepting one or 

 two branches with spikelets attached, draw only 

 the parts of the branches near the rachis. (b) 

 In like manner make a drawing of a side oat 



low do the branches of the spreading panicle differ from the branches of the 



M FlK 52. 



Oat culms frown from a single seed. This figure 

 illustrates very well the stooling of 



panicle, (c) 

 side panicle? 



8. The parts of an oat spikelet are quite similar to the parts of the wheat spikelet. Dis- 

 sect an oat spikelet as illustrated in Fig. 55, page 86. Make a neat drawing (natural size) of 

 the dissected oat spikelet. 



9. (a) Do you find a small sterile flower mar the center of the dissected spikelet? (b) It 



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