Lactarius indigo (Schw.) Fr. Cap 5-15cm across, convex-depressed with an inrolled margin at first; indigo blue when fresh, fading to grayish, then having a silvery luster, with deep green areas where bruised; sticky, smooth, zoned. Gills adnate, close, broad; indigo blue or paler to yellowish from the maturing spores, staining green when bruised. Stem 20-80 x 1-25mm, hard becoming hollow, often tapered toward the base; indigo blue to silver blue, spotted at times; sticky but soon dry. Flesh whitish, promptly turning indigo blue when cut, staining greenish. Latex deep indigo blue, becoming dark green on exposure to the air. Odor mild. Taste mild or slightly bitter or slightly acrid. Spores broadly ellipsoid to subglobose, amyloid, 7-9 x 5.5-7.5μ,; ornamented with a complete or broken reticulum, prominences 0.4-0.5µ high. Deposit cream. Habitat scattered or in groups on soil in oak and pine woods. Common in the southeastern North America, rarer farther north. Season July-October. Edible.(Never eat any mushroom until you are certain it is edible as many are poisonous and some are deadly poisonous.)