TAXONOMY 
247 
Flowers trimerous (having the parts of each whorl in threes or 
multiple thereof). 
Secondary growth in roots generally absent. 
Medullary rays generally absent. 
I. Order Graminales. — Graminacece or Grass Family . — Mostly 
herbs with cylindric, hollow jointed stems whose nodes are swollen. 
The leaves are alternate, with long split sheaths and a ligule. 
Fig. 120. — Pistillate and staminate inflorescences of corn (Zea mays). 
(Robbins.) 
