Interesting, but needs work.  That first like is ok for a description, but needs to be more specific.  Also, the last line is fine for your specific setting, but really isn't necessary if it's going to be used in other peoples games. 

This ring made of reeking pine can spread its rot to any non-magical wood.  As an action, you can touch this ring to nonmagical wood.  Every round afterward, the rot will spread 5 ft and reduce the affected wood to a foul pulp.  

Destroyed one of the rings in our campaign. It rotted away when I took a bath in salt water.

Sorry, there are only two left now

Does this include magically imbued wood?