The ornamental design for a planter, as shown and described.
FIG. 1 is a front elevational view of a planter showing my new design, the
right and left side and rear views (not shown) being identical thereto;
FIG. 2 is a top plan view, the bottom plan (not shown) being identical
thereto; and,
FIG. 3 is a perspective view.
The broken lines of FIG. 3 showing arrangements of flowers and plants, and
soil, are for illustrative purposes only and form no part of the claimed
design.