CHAPTER VIII. 



THE FRUIT AND SEED. 



The stigma of an ordinary grass consists of two divari- 

 cating plume-like structures composed of thin-walled cells. 

 When the paleae open these stigmatic plumes protrude, 

 one on either side, and readily catch pollen shed from the 

 dangling stamens and carried by the wind, and since the 

 pollen of the same flower is usually shed at a time when 

 the stigmas of many neighbouring plants are mature, 

 there is every opportunity for cross-fertilisation. (Fig. 33.) 



In some cases, however, e.g. Anthoxanthum, Alopecurus, 

 the flowers are proterogynous, the stigmatic plumes being 

 ready for pollination some time before the pollen is shed 

 from the anthers of the same flower ; whereas in most of 

 our grasses the pollen begins to scatter before the stigmas 

 are ready (protandrous). Among exotic grasses, many are 

 dioecious or monoecious — i.e. the flowers contain stamens 

 only or ovary only, on each plant, or on different inflores- 

 cences of the same plant respectively — and even in our 

 own Holcus and Arrhenatherum this state of affairs is 

 partially represented, since one flower of the spikelet is 

 male only. 



In some grasses, e.g. Rye, however, it appears im- 



