AN UNUSUAL TYPE OF PROLIFERATION IN 

 AGROPYRON CRIST ATUM 



C. V. Piper 



The illustration shows a case of 

 proliferation in Agropyron cristatum 

 (L.) Beauv. which occurred in a plot of 

 grass of this species at Redfield, S. 

 Dak., in 1920. It will be noted that 

 four of the spikelets are replaced by 

 elongated leafy branches, a not un- 

 common teratological phenomenon in 

 various species of Agropyron and other 

 grasses, but in this example consider- 

 ably longer than usual. In about 

 twelve other spikelets the axis above 

 the glumes is elongated and one or more 

 of the lower lemmas appear as some- 

 what elongated bracts, the remainder 

 of the spikelet being normal. In all 



of these modified spikelets the two 

 glumes (empty glumes) remain un- 

 changed — that is, exactly like those in 

 the normal spikelets. 



Proliferating spikelets — that is, those 

 which elongate into leafy sterile 

 branches — are very common in many 

 grasses. Spikelets in which the axis 

 elongates arid only a few of the lower 

 lemmas become sterile while the re- 

 maining ones remain fertile, seem not 

 to have been reported. At least a 

 search in the literature for such exam- 

 ples revealed no cases reported among 

 grasses. 



AGROPYRON CRISTATUM (L.) BEAUV. 



1. Normal spike. 2. Normal spikelet. 3. Abnormal spike, four of the spikelets changed into 

 leafy branches and twelve others each with the rachis elongated and the lower lemmas somewhat 

 elongated. The glumes (empty glumes') remain normal in all the teratological spikelets. 

 4. Abnormal spikelet with the lower internodes of the rachis elongated. (Fig. 20.) 



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