The boletes of Michigan, by Alexander H. Smith and Harry D. Thiers.

36

THE BOLETES OF MICHIGAN

readily; veil thick, tough, membranous, with a pale buff exterior of
unpolished appearance at first, the inner layer slowly gelatinizing, the
lower edge adnate to stipe but tending to separate from it in places,
staining dark brown when handled, breaking away from the pileus margin to leave a gelatinous annulus.
Spore deposit olive-mustard-yellow fresh, on standing (at least on
old leaves and on the apex of the stipe) discoloring slowly to "snuffbrown" or darker (a dark yellow-brown). Spores 6-9 X 6-8 /, globose to
subglobose, smooth, yellowish hyaline in water mounts, ochraceous to
pale bister in KOH, pale tawny to darker in Melzer's, with an inconspicuous hyaline outer sheath, unornamented, wall thickened slightly.
Basidia 4-spored, 18-22 X 9-11 L, hyaline in KOH individually,
nonamyloid. Pleurocystidia scattered to abundant, 20-32 X 8-12 i,
fusoid-ventricose with subacute apex, content dingy brown in KOH as
revived, nonamyloid. Hymenium dark brown in KOH. Cheilocystidia
abundant, similar- to pleurocystidia, extending down the stipe as caulocystidia.
Tube trama gelatinous and consisting of hyphae diverging from a
central strand which is brownish when revived in KOH, and hyphal walls
and the cell content nonamyloid. Epicutis of pileus a thick (over 200 u)
layer of appressed narrow gelatinous nearly hyaline hyphae as revived in
both KOH and Melzer's. Tramal body of brownish floccose tissue as
revived in KOH, nonamyloid. Clamp connections present, abundant in
some basidiocarps but difficult to find in others.
Habit, habitat, and distribution.-Solitary to gregarious under hardwoods, especially oak in Michigan, not uncornmon in June and again in
September.
Observations.-Although this is perhaps the fleshiest species of
Suillus in Michigan, we have found no one who would recommend it for
the table. It is one of the most frequently collected species in modern
"suburbia" where original forest trees have been left as shade trees and
the ground cover cleaned out but not planted to grass. It seems apparent
that the fungus must have been living in the original forest, but did not
fruit (or does not) as readily under those conditions as it does after the
habitat has been changed.
Material examined.-Barry: Mazzer 4232. Jackson: Smith 18375,
18571, Zehner, 242. Livingston: Hoseney 348, 1032; Mazzer 4201;
Smith 6067. Montcalm: Potter 13521. Washtenaw: Homola 1039, 1097;
Hoseney 33, fall 1965; Kauffman 10-19-07, 7-21-17; Smith 9612,
15138, 15240, 18663, 18708, 62495, 62557, 64130, 74482, 64513,
66448, 72525, 72854, 72870; Thiers 4508.