72 



FIRST BOOK OF GRASSES 



but more commonly they are racemose on the main 

 axis (as in Fig. 62). The rachis is sometimes winged, 

 and in a few species the broad wings fold up over the 

 base of the spikelets. 



In Reimarochloa (represented by but one species 

 in the United States) the spikelets are arranged as 

 in Paspalum, but both glumes are suppressed except 



in the uppermost 



spike let. (Recall 

 Lolium, Lesson V, 

 Fig. 27, page 36). 

 If it were not for its 

 obvious relation- 

 ship to Paspalum, 

 in which an occa- 

 sional first glume is 

 developed in sev- 

 eral species and reg- 

 ularly in a few, the 

 spikelet of Reima- 

 rochloa might be 

 taken to be strictly 

 1-flowered with 

 only the first glume 

 suppressed except in the terminal spikelet. 



In Paspalum we have seen a slightly broadened 

 rachis (Fig. 63). In Stenotaphrum, or St. Augustine- 

 grass (Fig. 64), the rachis is broad, thick, and corky, 

 and the spikelets are partly embedded in it. At 

 maturity the rachis breaks up into short joints with 



Fig. 64. A, part of raceme of Stenotaphrum 

 secundatum, front view showing spikelets; 

 B, back view of three joints. 



