North American species of Lactarius / L. R. Hesler, Alexander H. Smith.

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North American Species of Lactarius

Imai states that this species is related to L. glaucescens Crossl.
but is distinguished by its yellow pileus, less crowded and broader
lamellae, and the mild taste.
74. Lactarius controversus (Fr.) Fr.
Epicr. Syst. Mycol. p. 335. 1838
Agaricus controversus Fries, Syst. Mycol. 1: 62. 1821.
Illus, P1. 107.
Pileus (4)7-16(22) cm broad, convex, depressed to infundibuliform, white or whitish, sometimes with stains which vary in color (in
North American collections, lavender, smoky lavender, lavenderbrown, or vinaceous to pink), viscid but soon dry, the surface appressedfibrillose, the margin inrolled and short pubescent-tomentose at first,
usually with narrow zones in the marginal area. Context white, firm,
odor mild to slight and pleasant, taste slowly but strongly burningacrid. Latex white, unchanging, not staining, slowly acrid.
Lamellae adnate to subdecurrent, pale pink to "light vinaceousfawn," becoming pinkish cream in age, close or crowded, narrow,
some forking near the stipe.
Stipe 2.5-5(8) cm long, 16-25(50) mm thick, white, when wet
somewhat tacky, soon dry, sometimes spotted, sometimes eccentric,
equal or tapering downward, stuffed then hollow.
Spore deposit cream color to "pale pinkish cinnamon." Spores
from sections 6-7.5 X 4.5-5,, ellipsoid, with a small but distinct
plage lacking diffuse amyloid material; ornamentation proper a broken
to a partial reticulum with many free ends, some isolated particles
and warts present, prominences 0.2-0.5 Mu high.
Basidia + 37 X 7.5 pu, 4-spored. Pleurocystidia of the intermediate
type (30-45 X 3-5 M), aciculate and with one or more subapical
constrictions, often buried in the hymenium. Cheilocystidia + basidiolelike. Gill trama lacking rosettes, the lactifers inconspicuous. Pileus trama
heteromerous; lacking dextrinoid debris; cuticle a distinct ixocutis of
collapsing hyphae mostly thin-walled. Stipe cortex with rosettes, walls of
the sphaerocysts slightly thickened and refractive. Stipe cuticle a thin
narrow zone of appressed-interwoven hyphae, the hyphae matted down at
the surface (not clearly either "dry" or "viscid").
Habit, habitat, and distribution.-On soil under Salix and Populus,
widely distributed, summer and autumn.
Observations.-The small spores, narrow pleurocystidia and
cheilocystidia, white matted-fibrillose to glabrous pileus (often