What is Secondary growth?
[[File:Tree swallowing lamp post.JPG|thumb|Tree growing around a lamp post, an example of secondary growth.]] '''Secondary growth''' is a term in [[botany]]. It usually occurs in [[Dicotyledon|dicot]]s and [[Gymnosperm|gymnosperms]]. It makes the stems and roots thicker. It is one of the features of trees whereby they come to have long lives. [[Monocots]] and [[Pteridophyte|Pteridophytes]] usually lack secondary thickening, with the exception of ''Isoetes''. That is a quillwort, a [[genus]] of [[Lycopod|lycopods]]. [[Category:Botany]]