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

Appendix I

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tinct cellular layer in the aggregate, the end cells covered with a distinct but thin slime layer (in KOH or in Melzer's), content of cells pale
ochraceous-tan in KOH.
Material cited.-BELGIUM: Bas 5025 (L); ENGLAND: Dennis
(MICH); Orton 2994 (K); E. Kits van. Waveren, near Chichester, September 2, 1967, and September 5, 1967, near Bewdley September 5,
1967 (all L); Smith 80535; FRANCE; Bas 852 (L); Romagnesi, September 8, 1948 (type; PC); Shaffer 4192, 4319, 4387, 4615 (all MICH);
SWITZERLAND: Huijsman (TENN 30385).
Subgenus LACTIFLUUS
Lactarius subpiperatus Hongo
Mem. Fac. Liberal Arts Shiga Univ., Pt. 2, Nat. Sci. 14: 46. 1964
Illus. Hongo, I.c., fig. 9 (d.e.f.). Imazeki and Hongo, Coloured
Illus. Fungi of Japan II, fig. 205.
Pileus 5-8 cm broad, convex-umbilicate, then nearly infundibuliform, at first whitish then with dingy yellowish stains, dry, granular or
smooth, somewhat radially wrinkled in the center, margin at first involute, often undulating. Context relatively thick, solid, whitish, turning yellow on exposure to the air. Latex white, taste strongly acrid.
Lamellae decurrent, white then slightly yellowish, distant, narrow
(2-5 mm), occasionally forked, slightly intervenose.
Stipe 4-6 cm long, 15 mm thick, white then stained dingy yellowish, slightly tapering downward, almost solid, subrugulose, dry.
Spores 6-7.5 X 5-6 g, ellipsoid; warts minute, with fine to medium broad lines connecting the warts, usually not forming a complete
reticulum.
Basidia 3440 X 7-8 M, 2- and 4-spored. Pleurocystidia none except for pseudocystidia which are filamentous and scattered. Cheilocystidia 20-34 X 3-6 M, cylindric, clavate, or ventricose, not abundant.
Gill trama of interwoven hyphae, with lactifers. Pileus trama heteromerous. Cuticle scarcely differentiated. Caulocystidia 27-50 X 4-7,A,
cylindric, clavate, ventricose, scattered.
Habit, habitat, and distribution.-Gregarious on soil, in forest of
Quercus serrata, legit Tsuguo Hongo, 2768 (type, TENN), Otsu, Japan,
September 19, 1963.
Observations.-Hongo (1964) states that this species is intermediate between L. piperatus and L. vellereus, the almost glabrous pileus
showing its affinity to the former, and the distant gills to the latter. It is
distinguished from L. piperatus by the lamellae which are not crowded