septal pore cap (SPC), also termed the par-
enthesome. In contrast, the SPCs of Tremello-
mycetes and Wallemiomycetes are composed of
saccules or fingerlike projections arising from
the endoplasmic reticulum (SPCs are also occa-
sionally absent in both groups) (Wells and Ban-
doni 2001 ; Padamsee et al. 2012 ). The
intracisternal space of the SPCs of Agaricomy-
cetes is sandwiched by a fine electron-opaque
layer so that the SPCs altogether appear nine-
lamellate in optimal sections (the double-
sectioned cisternal membrane with three layers
each and the intracisternal lumen with three
layers). Variation in the perforation of SPCs
within Agaricomycetes was summarized by
van Driel et al. ( 2009 , and references therein).
The following account completes and correctsthis synopsis with new observations (by R.
Bauer) using serial sections. Accordingly,
within the Dacrymycetes/Agaricomycetes
union, four types of SPC are evident.
Imperforate to uni-perforate SPCs
(Fig.14.2a). Probably depending on the sec-
tion, no or only one median perforation of ca.
100 nm appears in one section of the series.
This type is typical for Dacrymycetes and
within Agaricomycetes for Sebacinales, Auri-
culariales, Trechisporales, theBotryobasidium
and Tulasnella clades within Cantharellales,
and the Hymenochaetaceae, Hyphodontia,
Coltricia, Kneiffiella, and Trichaptum clades
within Hymenochaetales [for the taxa and
clades see Hibbett ( 2006 ) and van Driel et al.
( 2009 )].Fig. 14.3Sebacinales (a,b), Auriculariales (c,d), and
Cantharellales (e,f). (a)Sebacina epigaea.(b)Cratero-
colla cerasi.(c)Pseudohydnum gelatinosum.(d)Exidia
truncata.(e)Craterellus tubaeformis.(f)Clavulina cris-
tata. Photos by Michael Wood (a,e,f;http://www.
mykoweb.com) and Jaroslav Maly (b–d)378 D.S. Hibbett et al.