Lactarius chelidonium var. chelidonioides (Smith) Smith & Hesler.
Cap 3-8cm across, flattish with a distinctly depressed center, becoming shallowly funnel-shaped; dirty azure blue with orangy-brown patches or concentric rings in young specimens, becoming dull reddish brown staining green or olive in older specimens, often mottled with watery spots; smooth, sticky then dry. Gills decurrent, narrow, crowded; dingy yellow and darker, stained green or olive-brown and stained darker green in old caps. Stem 30-60 x 10-25mm, hollow, sometimes enlarged toward the base; similar color to cap but paler; dry. Flesh azure blue toward top, more yellowish near gills. Latex dirty yellow to yellowish brown; scanty. Odor slightly sickly, like Morchella esculenta (q.v.). Taste slightly peppery after a few minutes. Spores ellipsoid with an oblique sterigmal appendage, amyloid, 7-9 x 5-6.5μ; ornamented with prominences 0.5-1μ high of irregular branches, forming at most a broken reticulum. Deposit pale buff. Habitat gregarious on soil in coniferous woods, particularly under pine. Frequent. Found in northeastern North America. Season August-October. Edibility not known.