GRAMINACE^ i8i 



time, the stigmas wither and secrete honey which is sipped 

 by the imprisoned midges. Only then do the anthers ripen 

 and pour out their pollen, with which the captive-insects 

 become sprinkled. Finally the bars of the prison are loosed, 

 for the hairs forming the palisade wither and allow the flies 

 to escape dusted with pollen. The whole inflorescence is 

 therefore specially constructed so as to accomplish the cross- 

 pollination of the flowers by the agency of small flies. 



GEAMINACEiE (Grass Family) 



"Herbs. Stems cylindrical, hollow except at the nodes. 

 Leaves alternate, ligulate, with sheaths usually split down 

 to the base. Flowers ranged in spikelets with chaffy bracts. 

 Flowers regular, inconspicuous, hypogynous. Perianth absent 

 (or perhaps represented by two minute scales). Stamens 

 usually three, with dangling anthers ; ovary one-chambered, 

 with one ovule ; stigmas usually two, feathery or brush-like. 



Types : WHEAT, COUCH-GRASS, MEADOW-GRASSES, 

 FOXTAIL, COCKSFOOT. 



Our British Grasses are herbs with cylindrical stems which 

 are hollow except at the nodes. 



The leaves are alternate, and ranged in two rows along the 

 stem. They are long, narrow, parallel - veined, and usually 

 have prominent ribs. The base of the leaf surrounds the 

 stem in the form of a sheath which is, in most cases, spHt 

 down one side. At their regions of insertion the sheaths are 

 thickened, and thus cause the nodes to appear swollen. Each 

 leaf has a ligule (see page 15). In the bud the leaves are often 

 rolled ; but the Meadow-Grass and Cocksfoot have their young 

 leaves folded. 



Branches which bear foliage-leaves arise only in the axils of 

 radical leaves. In some Grasses these axillary branches burst 

 through the enveloping sheaths, and, running horizontally 

 underground for some distance, lead to the formation of sym- 

 podial rhizomes with scale-leaves, as described on page 25. 

 On the other hand, the branches which arise in the axils of 

 the radical leaves may at once ascend, after either bursting 

 through the surrounding sheaths or pushing their way between 



