What is the difference between a monocot and dicot stem?

Question

Which one is a pine stem?

Which one is a corn stem?

State the structural features that distinguish the monocot from the dicot.

Answer 1

A pine is neither a dicot or monocot.  Dicots and monocots are the two major groups within the angiosperms (flowering plants).  A pine is a gymnosperm, a non-flowering seed plant.

Anyway, corn is a monocot.  Monocots have their vascular bundles scattered throughout the stem when viewed in cross section.

A typical dicot that is used in many general textbooks is a bean.  In cross section the vascular bundles are in a ring when viewed in cross section.

Many texts use the generalization that monocots do not have secondary growth--they only have primary growth from the apical meristem.  Whereas some dicots, in addition to primary growth, have secondary growth from so-called lateral or secondary meristems.

One example of a lateral meristem is the vascular cambium--it produces xylem and phloem.  The xylem forms what is commonly called wood and accounts for most of the increase in the girth of the stem.  You would not find a vascular cambium in a monocot.