Lactarius atroviridis has a rugose blackish-green convex cap with vaguely concentric scrobiculations, especially along the scurfy inrolled margin and a central deeply depressed disc. Attached whitish-buff gills are close, white, often forked and of varying lengths. They bruise and stain greenish with age. The spore print is white to cream. The latex is white, unchanging and turns gills greenish. The stipe is concolorous with the cap and scrobiculate. It is found in mixed woods, especially with oaks in summer and fall. Taste is mild to acrid. Inedible.