110 A TEXT-BOOK OF GRASSES 



scales. These throw up a culm several inches in thickness, 

 covered with large scales, and grow many feet in height 

 before they develop foliage-branches. In perennial 

 stemmed bamboos may be observed scales also upon the 

 lower portion of branches. These scales often show transi- 

 tions to foliage-leaves, the upper bearing rudimentary 

 blades. 



Scales are always produced upon rhizomes. Their 

 chief function appears to be that of protection to the 

 growing point as the rhizome is forced through the soil. 

 The scales develop rapidly in the form of a bud at the end, 

 overlapping and sharp-pointed. The terminal portion 

 of some vigorous rhizomes is as hard as wood and as sharp 

 as an awl. By the elongation of the internodes, the scales 

 behind the growing point are separated and may become 

 lacerated or otherwise lose their original shape. 



141. Bracts are reduced leaves that are borne on shoots 

 above the foliage-leaves. They may be discussed under 

 two heads, those that are in or near the inflorescence, 

 and those that are specially modified in the spikelet. The 

 latter will be considered in a future paragraph dealing 

 with the spikelet. 



Among flowering plants in general, bracts are usually 

 found subtending each branch of the inflorescence down 

 to the individual flower. In grasses these bracts are rarely 

 present. In large panicles, as in some species of Bromus, 

 the lower branches may be subtended by small bracts or 

 there is at least a ridge representing a bract. Sheathing 

 bracts are found in various genera, especially among 

 AndropogoneaB, at the base of the entire inflorescence or 

 of certain portions of it. In some grasses, the uppermost 

 leaf below the inflorescence may have a much-reduced 

 blade, for example many species of Poa, but such leaves 



