The North American species of Pholiota, by Alexander H. Smith and L. R. Hesler.

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The North American Species of Pholiota

Smith 799. ONTARIO: Kelly 994; Smith 4432, 4375. QUEBEC: Smith
61702.
Section Hygrotrama
The species placed here shows thicker spore walls than occur in other
stirps when spores of the same size are compared. The apical pore is
obscure in some spores. This is the genus Pachylepyrium of Singer, who
states (1963, p. 559) that the genus differs from Kuehneromyces in the
color of the spores and the character of the surface of the pileus and in
habitat. We do not agree that the degree of thickening in the spore wall
is of any generic significance here since throughout the genus the spore
wall is not what one would term thin in the sense that the term applies
to the Tricholomataceae. To us the situation is more like that found by
Smith (Smith &8 Zeller, 1966) in Rhizopogon. In this genus the spore
wall varies from thin up to 0.5 up thick (which is scarcely to be regarded
as thin), but Morten Lange found one species with spore walls up to or
over 1.5 u/ thick. As to spore color, it is within the range of that of subg.
Pholiota. Hence there is no use trying to use either of these characters to
establish a genus in this complex. In the absence of E M photographs of
the spores of Pholiota in general it is premature to use the number of
layers in the wall as a generic character here. In all of the stirpes so far
discussed for this subgenus the spores approach those of P. subangularis
in wall thickness.
We have one species known to date in North America: P. subangularis.
5. Pholiota subangularis nom. nov.
Kuehneromyces carbonicola Smith, Sydowia Suppl. 1: 53. 1957. (non
Pholiota carbonicola Singer, 1963)
Illustrations: Text figs. 175-176; pl. 1.
Pileus 1-3 (4) cm broad, broadly convex with an incurved margin,
expanding to plane or nearly so, "natal-brown" at first but gradually
becoming paler (to "warm-sepia"), hygrophanous, fading to a bright or
a dingy tawny, lubricous, glabrous or with a faint marginal zone of
pallid fibrils from the thin veil. Context fragile, watery brown fading to
buff; odor and taste none.
Lamellae adnate, seceding at times, more or less ochraceous tawny
(paler when young, darker in age), broad, edges somewhat fimbriate.
Stipe 3-5 cm long, 2.5-3.5 mm thick, lower three-fourths silky from
the remnants of a thin veil and at first with a superior fibrillose zone
where the veil breaks, apex naked and shining, watery brown above,
darker brown below and becoming bister from the base upward in age.