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

170

North American Species of Lactarius

3. Not as above..................................................... 4
4. FeSO4 on pilear context vinaceous to redder; gills staining brown
slowly................................. L. hygrophoroides var. rugatus
4. FeSO4 staining pilear context slowly to olive-gray; gills where injured
staining pink to lavender and at times the stains finally avellaneous to
wood-brown....................... L. hygrophoroides var. lavendulaceus
41. Lactarius pervelutinus sp. nov.
Illus. PI. 32.
Pileus 4-4.5 cm latus, siccus, velutinus, ferrugineo-brunneus vel
ferrugineo-aurantiacus, mitis; latex lacteus vel cremeus, constans;
lamellae angustae, subdistantes, brunneo-maculatae; stipes brevis, 3
cm longus, 18 mm crassus, firmus, lamellis concolor, siccus; sporae
6-7.5 X 5-6,u. Specimen typicum in Herbarium University of Michigan
conservatum, legit prope Ann Arbor, Michigan, 15 Aug 1973, Smith
84431.
Pileus 4-4.5 cm broad, convex-depressed, margin incurved, surface dry, velvety, with a hoary sheen, ferruginous-brown to orangerufous, ochraceous at the margin. Context firm brittle, yellowish white,
odor slight, taste mild, FeSO4 greenish gray slowly (overnight), KOH
on cuticle weakly olive-buff. Latex milk-white to (against white paper)
yellowish, staining lamellae slowly to vinaceous-pink then lilac-brown,
mild.
Lamellae narrow, broadly adnate, subdistant, cream color when
young, staining as indicated above but stains not conspicuous.
Stipe short, 3 cm long, 18 mm thick, equal, hard, ~ concolorous
with the gills (pallid cream), dry and dull.
Spore deposit creamy white in a thick deposit. Spores 6-7.5 X
5-6,u, broadly ellipsoid; plage hyaline, broad, lacking an amyloid
coating; ornamentation in the form of a broken reticulum to lacking
any semblance of a reticulum (the ridges and warts not connected),
prominences less than 0.2 uL high.
Basidia 4-spored, narrowly clavate, 40-52 X 6-8,u. Pleurocystidia:
macrocystidia none; pseudocystidia filamentous, embedded, inconspicuous. Cheilocystidia: (1) subfilamentous, 30-40 X 3-7,u, flexous; (2) narrowly fusoid-ventricose and obtuse, 26-35 X 5-8,u; (3)
cystidioid ends of lactifers clavate to mucronate, 6-12 ju broad (rarely
with apex greatly inflated). Gill trama lacking rosettes; lactifers
abundant, yellowish and refractive in KOH, 5-11 wide. Pileus trama
rather weakly heteromerous, globules numerous in Melzer's mounts,
lactifers large, numerous, conspicuous. Pileus cuticle a thick basal
cellular layer 3-6 cells deep, walls colored slightly in KOH (seen