A celadon green drip glaze planter with striated diamond pattern and drainage hole by Cookson Pottery.  The planter measures 7 1/4" long, 5 1/8" wide, and 3 3/4" high.  The bottom is marked "CP-13 USA."  The condition is very good, with no chips, cracks, or crazing. 

Cookson Pottery of Ohio

Cookson Pottery was founded in 1945 by Gerald Cookson in Roseville, Ohio.  Cookson manufactured garden ware such as planters and vases and was in operation until the early nineties.