Arabis aculeolata is a species of flowering plant in the mustard family known by the common name Waldo rockcress.

This is a perennial herb growing from a tough caudex covered in large hairs and the bases of leaves shed in previous seasons.

The stems are dark in color, often reddish or purplish, and are coated in stiff white hairs.

They are oval-shaped, green in color and sparsely covered in coarse white hairs, up to 4 centimeters long, and with smooth or wavy edges.

[3] It is native to a small range in the mountains of southern Oregon, where it is an uncommon member of the serpentine soils flora.