Photo: © Steve Trudell
Lactarius kauffmanii
Hesler & Smith

Pileus: 2 - 9 cm broad; when young convex becoming planar and finally depressed at maturity, at times becoming funnel-shaped; margins inrolled at first, becoming straight and finally uplifted and flaring, exceeding gills, straight and even at times striate and grooved; surface moist to viscid to glutinous, smooth, often uneven and lumpy; when young brownish orange to light brown on disc and dark brown on margins, when mature greyish, orange brown to dark brown, evenly or at times fading to brownish yellow to golden light brown towards margins, at times edges reddish white to pallid; context 0.7 - 1.0 cm at junction of stipe, cuticle thick, spongy to firm, moist, colour pallid to whitish to brownish; taste mild to acrid; odour indistinct to variously described as ‘mushroom like’ ‘metallic’, ‘chemical’ to ‘household cleaner’, ‘sweet’.

Latex: White, changing to olive green, at times yellow brown, taste mild at first then peppery.

Lamellae: Horizontal to decurrent, average to crowded, narrow to broad, 4 mm wide, at times forking; edges even; colour orange white when young, darker when mature (reddish white), spotting golden brown, 3 lamellulae.

Stipe: 2 - 8 cm long X 0.5 - 2.0 cm wide, slightly tapering upwards to even, flexuous, tacky to viscid, at times striate, smooth to lumpy at times scrobiculate, same colour as gills (orange white), pale orange, darkening when bruised; context moist, stuffed to solid becoming hollow when mature, fragile, same colour as stipe surface.

Microcharacteristics: Spore print white to yellow; spores broadly ellipsoid, 7 - 10 X 7 - 8 µm, with amyloid ridges; no apparent hymenial cystidia.

Comments: Lactarius kauffmanii is common in these forests and can be confused with L. pseudomucidus but is differentiated by having a stipe that is pale and the same colour as the lamellae. L. pseudomucidus has a darker stipe that is the same colour as the pileus. The latex of L. kauffmanii is white that dries green, while L. pseudomucidus also has white latex but it doesn’t change colour.

Further Reading:

Hesler, L.R. and A.H. Smith. 1979. North American species of Lactarius. Univ. Michigan Press. Ann Arbor, Mich. pp 841.

Methven, A.S. 1997. The Agaricales (gilled fungi) of California. 10. Russulaceae II. Lactarius. Mad River Press. Eureka Ca. pp 78.