This is a posted private mailing card , dark green with gold printing, a clover with various St. Patrick's Day / Irish greetings.
Posted March 1906 in Pennsylvania, 1 cent stamp.
Normal wear as is common with old postcards. May have creases, corner bumps, ink on either side, etc.
Examine the condition as shown in photos.
The postcard measures 3.5"x5.5"