GRASSES, 108 
unequal in length, and each spikelet bears 4 or 5, or some- 
times more, flowers. A similar structure prevails in Rye- 
grass (Lolium perenne), only the upper flowering-glume is 
missing altogether. 
In Barley (Hordeum vulgare) the spikelet contains only 
one flower, both the empty glumes and the flowering-glume 
are awned, and the palea is closely adherent to the fruit. 
The relation of the flowers of gyasses to those of other 
monocotyledons is not at first sight apparent, but the exami- 
nation of those forms, such as Bamboo, which have under- 
gone less modification than our ordinary grasses, shows how 
the present structure has been arrived at by suppression of 
various parts. In a typical monocotyledon such as Lily the 
flower consists of fifteen floral leaves, arranged in five whorls. 
In Bamboo the flower is quite regular, but there are only 
twelve parts—viz., 3 perianth-leaves, 6 stamens, and 3 carpels. 
In ordinary grasses (¢.g., Oats) not only is the outer whorl 
absent, but the posterior leaf of the inner whorl is also sup- 
pressed, while the two which are present are reduced to 
minute scales (the lodicules). Similarly, the 3 stamens of the 
inner whorl and the anterior carpellary leaf are wanting. 
This structure will be made more clear by an examination of 
the accompanying floral diagrams. 
ne (B.) (C.) 
Fig. 207. Theoretical diagram of (A) Bamboo, (B) most Grasses, 
(c) Nardus. (After Sachs.) 
