Grade. 

 Date. . 



EXERCISE 6 

 GRASS FAMILY 



Object. To learn the characteristics of the Graminese (Grass Family). 



Materials. Corn and oat plants, wheat and barley spikes. 



Explanation. Both the cereals and the grasses belong to the Family 

 Gramineae, the members of which are similar in structure. Agriculturally, 

 this family is more important than any other. 



Roots. The Graminese have fibrous roots. See Exercise 5. 



Stems. The typical stem of the Graminese is hollow, is circular or 

 flattened in section and is divided by nodes. 



Drawing I. Draw the transverse section of a corn stem. 



Drawing II. Draw the longitudinal section of a short piece of corn 

 stem which includes a node. 



Drawing III. Draw a longitudinal section of a sheath ring on oats. 

 Be careful to show the relation of the ring to the node. This ring occurs 

 on oats, bent grasses and fesque grasses. 



Leaf. The leaves of the Graminese are arranged in two rows alternating 

 up the stem. The leaf consists of a sheath and a blade. 



Drawing IV. Draw the junction of the leaf and the blade on a corn leaf. 

 Show sheath, ligule, auricle and blade. 



Spikelets. The spikelets of the Gramineae have (1) a pair of outer 

 glumes; (2) a flowering glume and palea surrounding each kernel; (3) an 

 undeveloped flower represented by the axis and empty glumes. 



Drawing V. Arrange the oat spikelet parts in the order in which they 

 occur. Draw ( X 3) and label them carefully. 



Drawing VI. Draw a wheat spikelet in the same manner. 



Drawing VII. Draw the barley spikelet. Note that three spikelets 

 occur at a node instead of one as in oats and wheat. 



Observation. 1. The class should observe a corn ear (Fig. 9) and tassel 

 and note the similarity in structure to the three spikelets drawn. 



2. Observe resemblance between spikelets drawn and spikelets of timothy, 

 rye grass or one of the other grasses. 



Discussion. After reading Sargent, F. L., Corn Plants, pages 11-34, 

 Cambridge, 1899, the instructor should discuss with the class the ways in which 

 the structure of the Gramineae enables them to cope with their environment. 



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