[Illustration: BOLETUS SUBTOMENTOSUS. B. CHRYSENTERON].
[Sidenote: =Caution advisable=]
Another species having this peculiar property of "turning blue" even in
a more marked degree, and named, in consequence, the _B. cyanescens_,
though always heretofore considered poisonous, is now pronounced by
certain prominent mycophagists to be not only harmless but esculent. It
is still advisable, however, to caution moderation in its use as food,
if only on the ground of idiosyncrasy. The spores of this species are
_white_, which, with the more minute tube openings, form a sufficient
discrimination from _subtomentosus_. The spores should be obtained by
a deposit on black or dark-colored paper. The flesh is white also.
Other blue-stain species, such as _B. alveolatus_ (Plate 24), are still
considered with suspicion, presumably groundless.