CH. I] 



The Morphology of Grasses 



15 



by the way in which the spikelets are attached to the main 

 axis. If they are borne directly upon the rachis, as in Fig. 27, 

 we have a spike of spikelets or briefly a spike (see Couch-grass). 

 If they are supported upon primary or simple branches we have 

 a raceme. In the majority of species, however, the spikelets are 

 borne on secondary, tertiary, or even further subdivided branches, 

 and this compound class of inflorescence is a panicle of spikelets 



u.gi--- 



-Lgl 



Fig. 18 Fig. 19 



Fig. 18. Diagram of a grass spikelet (Festuca rubra) showing the alternate 

 arrangement of the flowers (Nos. 1 6), within, or above, the empty glumes. 

 Lgl. lower glume, u.gl. upper glume, o.p. outer palea, and i.p. inner palea of 

 the first flower. The stamens are represented by crosses. Ov. ovary, Lod. 

 lodicules, R. rachis. 



Fig. 19. The same, showing the manner in which the spikelet breaks up when 

 the " seeds " (1 6) are ripe. R. rachillae. Usually one or more of the upper- 

 most flowers fail to produce mature " seed." 



or briefly a panicle (see Oat, Fig. 14). It is evident that panicles 

 may differ very much in appearance according to the relative length 

 and stoutness of the branches. Thus they may be erect, close, 

 or even spike-like ; or long, loose, spreading, or drooping ; or they 

 may come anywhere between these extremes in structure and 

 appearance (see Figs. 46, 71, 73 and 87). 



