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

542

North American Species of Lactarius

three cells. Stipe cuticle a turf, often more or less flattened down, of
caulocystidia, 25-53 X 3-7 tz, cylindric or ventricose, arising from interwoven hyphae; rosettes present.
The following data are from Smith 80352: Spores (from sections) 8-9
X 7-8 p, subglobose to broadly ellipsoid, with a distinct plage usually with a
horseshoe-shaped plaque of diffuse amyloid materials; ornamentation in
the form of a broken to partial reticulum of relatively regular ridges,
ornamentation 0.5-1.5,u high.
Basidia 50-60 X 9-12,t, 4-spored. Pleurocystidia: macrocystidia
not observed; pseudocystidia present as filaments with refractive content, scattered, flexuous to contorted. Cheilocystidia not reviving. Gill
trama with pallid (in KOH) inconspicuous lactifers, content spangled to
inconspicuous, no rosettes seen. Pileus trama heteromerous, lactifers
pallid in KOH, content spangled; no dextrinoid material observed.
Pileus cuticle a modified trichoderm of vertically oriented hyphae with
lower cells somewhat inflated (~ angular as revived), end cells subcylindric to tapering forming a lax uneven turf, the cuticular zone
distinctly cinnamon-brown in KOH, "pileocystidia" 10-52 X 4-6 u, at
times septate. Stipe in poor condition (not studied).
Note. The height of the spore ornamentation covers the range for
L. picinus but also exceeds it. This collection, however, is very close
to Neuhoffs concept of L. picinus. It was obtained from the exhibit of
fleshy fungi at the Davos (Switzerland) foray.
At present we still do not have authentic records of the species
from North America. L. picinus var. americanus we now consider a
synonym of L. lignyotus var. lignyotus in which the preliminary red
staining was missed. It should be noted that in North American collections of L. lignyotus the stains slowly change to brown.
Lactarius pterosporus Romagnesi
Rev. Mycol. (Paris) 14: 108. 1949
Illus. Fig. 173.
Pileus 4-10 cm broad, soon broadly convex with a depressed disc,
at times also with a pointed umbo, often (or indeed in large specimens
almost always) warty and radiately rugulose, color (over a cream to
ocher-yellowish ground) umber to dark sooty brown with an accent of
ocher-fuscous, often entirely ocher brownish, or with dingy gray portion, at times spotted both colors, the disc often brighter (more rusty
tones), with bent-in margin, the margin soon spreading and in age in
part wavy and also lobed, velvety pruinose, fading in streaks, in general
dry but in moist weather also slightly slimy; injured places carmine-red,