B
aral
& M
arson
: Deltopyxis triangulispora gen. et sp. nov.
181
were usually broken only terminally, but are quite
easy to break near the trunk due to an often ad-
vanced wood decay (white rot) caused by Vuil
leminia. Sometimes they were already broken
towards the trunk and hang on lower branches.
The apothecia of Deltopyxis triangulispora are
preferably found on the very thin layer of the fruit-
bodies of Vuilleminia, either when these were still
whitish to skin-coloured, or on the darker, more
grey-brown to olivaceous marginal regions (Figs.
3a,e, 4b-c). D. triangulispora may also sparsely
occur on bark remote from Vuilleminia, and here
usually over small holes or clefts of the periderm
(Figs. 3b, g, 4d).
In the collections on Salix and Ilex no Vuilleminia
could be noted at all, however. Here the branches
were partly or entirely decorticated, and the apoth-
ecia grew mainly on wood, though often close to
other corticioid basidiomycetes (Peniophora, Hy
phodontia). Also in a collection on Prunus spinosa
from Därebësch (H.B. 4571a) no Vuilleminia could
be observed, instead, the branch was entirely cor-
ticated.
Frequently, Deltopyxis triangulispora occurs in
close association with species of Dactylospora
and Capronia, which likewise preferably grow on
senescent Vuilleminia. In a single collection, D.
triangulispora even grew partly on the apothecia
of Dactylospora (Fig. 4a). This raises the ques-
tion whether D. triangulispora shows some fun-
gicolous connection to Dactylospora rather than
Vuilleminia.
Aerophytic algae and various lichens and mosses
typically occur on the inhabited branches, but are
not always present. Sometimes they even cover
the apothecia and need to be removed by a jet of
water in order to detect the apothecia.
Relationship
. D. triangulispora was first consid-
ered by us to belong in the genus Tromeropsis
(Ascomycota incertae sedis). We studied T. mi
crotheca (P. K
arst
.) S
herwood
from several col-
lections and found that it differs in many points,
which appears to justify separation at the generic
level (see also the redescription by H
awksworth
&
S
herwood
1981). T. microtheca resembles D. trian
gulispora in the dark apothecia and multispored,
inamyloid asci that arise from croziers and open
by a large apical slit. T. microtheca differs in (1)
apothecia with an even margin, (2) an ectal ex-
cipulum of elongate, vertically oriented cortical
cells, (3) paraphyses with uninflated terminal cells
which are much longer than wide, young paraphy-
ses at the margin not formed as in Deltopyxis, (4)
strongly refractive, hyaline, KOH-soluble extracel-
lular drops between the paraphyses in the middle
and lower part of the hymenium, (5) an also later-
ally thickened ascus wall in the apical half of the
mature ascus (dead state), (6) a negative stain of
the entire ascus wall in CR
SDS
, (7) an often long,
flexuous ascus stalk, (8) 128-spored asci, (9) cy-
lindric-ellipsoid ascospores, and (10) occurrence
on coniferous substrate. Particularly the criteria
1-6 are considered diagnostic at the generic level.
The brief and rather inaccurate description of the
genus Microspora V
elen
. [non Microspora T
huret
1850, algae] with the single species M. dura
V
elen
., reported from coniferous wood by V
ele
-
novský
(1934), resembles Deltopyxis in some re-
spects. However, it was found to be a synonym of
Tromeropsis microtheca, based on a study of syn-
type collections preserved at PRM (B
aral
ined.).
Several members of Lecanoromycetes show
a certain similarity with Deltopyxis. The genus
Dactylospora K
oerb
. resembles not only macro-
scopically, but also in the construction of the ectal
excipulum. It differs in mostly 8-spored asci with
a strong hemiamyloid iodine reaction of the thin
lateral wall and a thick, strongly euamyloid apical
cap, also in brown, septate, elongate ascospores.
The genus Steinia K
örb
. resembles Deltopyxis in
its elongate-saccate, 16-spored asci and subglo-
bose ascospores, but the hymenium is hemiamy-
loid, also the asci possess an euamyloid tholus,
the paraphyses are much narrower and some-
what curved, and the apothecia have a convex im-
marginate disc (see K
antvilas
& M
c
C
arthy
1999).
The lichenized or lichenicolous genus Polysporina
V
ě
zda
resembles Deltopyxis in its multispored asci,
but deviates in richly branched and anastomosing
paraphyses with uninflated apices, and in amyloid
asci (see K
antvilas
1998). Macroscopically, Cat
illaria nigroclavata (N
yl
.) S
chuler
can easily be
confused with Deltopyxis, when the latter forms
larger apothecia.
The resinicolous genus Sarea F
r
. closely resem-
bles Deltopyxis in the saccate multispored asci
and the paraphyses tipped by pigmented exu-
date (see also H
awksworth
& S
herwood
1981).
It differs in asci with a strongly hemiamyloid thick
external gel and an inamyloid tholus with a ros-
trate opening mechanism. The ascus wall layers
are unstained in CR
SDS
, and the paraphyses are
sometimes branched above and below and are
not formed in the manner as described for Del
topyxis. The ectal excipulum is internally hyaline,
sharply delimited, heavily gelatinized, of vertically
oriented elongate cells. The pycnidial anamorph
of Sarea is quite similar to that of Deltopyxis.
