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

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THE BOLETES OF MICHIGAN

rather than under spruce, hemlock, and white pine mixtures. We at first
tried to identify our material with B. rhodoxanthus of Europe, but the
latter has a pallid pileus when young and paler colors generally at maturity. The deep purplish red of the pileus and the reticulum of the
stipe of B. rubroflammeus are constant and distinctive field characters.
We have not observed it to be as variable as Dick and Snell indicate for
their species.
Material examined.-Washtenaw: Smith 15352, 73004.
187. Boletus luridus Fries
Syst. Myc. 1:391. 1821
Leccinum luridum (Fries) S. F. Gray, Nat. Arr. Brit. PI. 1:648. 1821.
Tubiporus luridus (Fries) Karsten, Rev. Mycol. 3:16. 1881.
Dictyopus luridus (Fries) Quelet, Enchir. Fung. p. 160. 1881.
Suillus luridus (Fries) Poir. ex 0. Kurftze, Rev. Gen. PI. 3(2):535. 1898.
Illus. Pls. 139-40.
Pileus 5-12 cm broad, convex becoming broadly convex to shallowly depressed at maturity; margin sterile but neither crenate nor in
segments, incurved at first; surface dry and unpolished to somewhat
shiny, matted-fibrillose or with scattered minute fibrillose scales on the
disc, color variable, yellow to olive yellowish with a pinkish brick color,
margin in some "pale orange-yellow," disc near "cinnamon-buff' to
"clay color" or reddish, soon stained greenish blue where handled. Context thick up to 3 cm, floccose, yellowish ("primrose-yellow") to reddish, with a red line above the tubes when freshly cut, instantly deep
blue when injured; odor none, taste mild; dark blue in spots where
touched with Melzer's (after the natural bluing has faded).
Tubes free or at least deeply depressed, rarely decurrent, 1-2 cm
deep, yellow ("Reed-yellow") but quickly staining greenish blue when
injured; pores round small (about 3 per mm), deep red ("Morocco-red"
to "Pompeian-red" to "Hays-russet") but soon fading out to orange-red,
staining greenish blue when bruised.
Stipe 6-15 cm long, 1-3 cm thick, equal to clavate (base 4 cm
thick), often flared at apex, solid, bright yellow within or in the base
streaked reddish, soon staining blue to violaceous, surface dry, reticulate
at apex or extending nearly to base, pruinose to furfuraceous in addition, yellow ("chrome-yellow") overall or tinged cinnabar to blood-red
above and yellow lower down, or yellow above and reddish below.