The ornamental design for the rhizome rake, as shown and described.
FIG. 1 is a perspective view thereof.
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view;
FIG. 5 is a right side view;
FIG. 6 is a top plan view; and,
FIG. 7 is a bottom view of the invention.
The broken line showing of the rake handle is included for the purpose of illustrating environmental structure and forms no part of the claimed design.