396 THE STORY OF PLANT LIFE 



are found in all latitudes, and up to high altitudes. 

 Perhaps they may be said to obtain their greatest 

 development in the Temperate regions. In the 

 Tropics the Bamboos attain a great size and height, 

 up to 100 ft. 



Grasses are of herbaceous type, except the Bamboo. 

 Some are annual, but the majority are perennial. 

 The latter are branched from the lower nodes, and 

 in this case are tufted. A large number possess 

 rhizomes. The stems have nodes, with hollow 

 internodes, and often root at these points, where the 

 tissue is softer. The nodes when the stems are 

 decumbent may grow again and in this way assume 

 a vertical habit of growth. The stems are cylindrical 

 or compressed, usually hollow. The leaves are 

 often in two rows, alternate, narrow, with parallel 

 veins. They are sheathed at the base, the sheaths 

 split opposite the blade to the base, and end in a 

 ligule or transverse membrane, or in a ring of hairs 

 at the mouth, on the upper side of the leaf. The 

 leaves are, as a rule, without a leaf-stalk. They are 

 generally linear. In order to resist drought the 

 leaves are inrolled, with the stomata protected in the 

 groove thus formed. 



The inflorescence is usually a spike, panicle, or 

 raceme. The unit of the inflorescence is a spikelet. 

 Each consists of several alternate, inferior palese, or 

 flowering glumes with flowers (up to five) in the 

 axils, and at the base an outer, and an inner, glume, 

 which are empty, enclosing the flowering glumes 



