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

Subgenus Russularia

497

branched. Cheilocystidia aciculate, 30-50 X 3-6 A, often abundant.
Gill trama lacking rosettes; lactifers inconspicuous. Pileus trama
weakly heteromerous; lactifers inconspicuous. Pileus cuticle poorly
defined-of tangled hyphae often in fascicles, the cells tubular to inflated and end cells clavate to subcylindric. Stipe cuticle of longitudinally arranged appressed hyphae with hyphal ends and end cells
projecting, these 4-12, broad, no slime evident in the layer.
Further observations.-L. alpinus var. alpinus is characterized by a
delayed acrid taste (often rather strong), the strong development of
bright apricot-yellow tones in the pigmentation of the pileus, lamellae
becoming yellow or with a tint of salmon, a white spore deposit, association with Alnus, delicately fibrillose-squamulose pileus when faded,
and small size. For further comment see L. alpinus var. mitis.
Material cited.-ALASKA: Wells-Kempton 2907, 2908, 5561 (all
MICH); IDAHO: Smith 53301; NEW YORK: Peck, Haystack Mt.,
Adirondack Mts., August (type, NYS);- OREGON: Smith 19278;
WASHINGTON: Smith 40292, 40375, 40838, 40877, 40905, 41052,
48031.
184a. Lactarius alpinus var. mitis var. nov.
Illus. Pls. 138, 141a; fig. 168.
Pileus (2)3-6(8) cm latus, plano-papillatus demum late depressus,
vel subinfundibuliformis, udus demum rimulosus vel munite areolate
squamulosus, triste vinaceo-brunneus demum vinaceo-incarnatus vel
pallide vinaceo-cinnamomeus ("light pinkish cinnamon"); contextus
fragilis, subvinaceus, sapor mitis, odor debilis. Latex lacteus demum
serifluus, constans. Lamellae angustae, late adnatae vel decurrentes,
confertae, pallide avellaneae demum "orange-cinnamon." Stipes 3-5
cm longus, 10-15 mm crassus, fragilissimus, siccus, pallide avellaneus
demum incarnato-cinnamomeus, sparse fibrillosus demum glaber.
Sporae in cumulis albidae, 7.5-9 X 6-7.5 u. Macrocystidia 60-80 X (5)8 -11,i, mucronata. Specimen typicum in Herbarium University of Michigan conservatum est; legit sub Alni, Thorofare, Priest Lake, Idaho,
25 Sep 1972, Smith 82341.
Pileus (2)3-6(8) cm broad, at first nearly plane and with an inrolled margin, sometimes convex, sometimes papillate, in age the margin arched and disc broadly depressed, occasionally becoming broadly
vase-shaped, opaque, surface finely rimulose or over the disc finally
minutely squamulose from checking of the cuticle, appearing glabrous
and smooth when moist, quickly fading as if hygrophanous, dark reddish brown at first ("pecan-brown" or redder), soon fading to pale