New species and records of Crepidotus from Costa Rica and Mexico

Abstract

The new species C. pseudoantillarum and C. herrerae are described from Costa Rica and Mexico respectively. Records of C. pseudoantillarum from different localities in Mexico are presented, as well as the first report of C. albescens from Costa Rica. The newly described species, related to the taxa with smooth spores, gelatinous tissues and clamped hyphae, prompted us to make a reexamination of type specimens of C. albescens, C. antillarum, C. betulae, C. cinchonensis and C. phaseoliformis. On account of the morphological features are recognized: C. albescens (= C. betulae, C. phaseoliformis) and C. cinchonensis. The type of Tremellopsis antillarum is found to be a member of Crepidotus uber but under the name of C. antillarum s. auct. a distinct taxon has been obscured, which is being described here as C. pseudoantillarum. Descriptions, illustrations of microscopic features and discussions are provided.

Full text

Fungal Diversity
9
New species and records of Crepidotus from Costa Rica and Mexico
Bandala, V.M.1*, Montoya, L.1 and Mata, M.2
1Dept. Biodiversidad y Sistemática, Instituto de Ecología, A.C., P.O. Box 63, Xalapa, Veracruz 91000, Mexico
2Instituto Nacional de Biodiversidad, P.O. Box 22-3100, Santo Domingo de Heredia, Costa Rica
Bandala, V.M., Montoya, L. and Mata, M. (2008). New species and records of Crepidotus from Costa Rica and Mexico.
Fungal Diversity 32: 9-29.
The new species C. pseudoantillarum and C. herrerae are described from Costa Rica and Mexico respectively. Records
of C. pseudoantillarum from different localities in Mexico are presented, as well as the first report of C. albescens from
Costa Rica. The newly described species, related to the taxa with smooth spores, gelatinous tissues and clamped
hyphae, prompted us to make a reexamination of type specimens of C. albescens, C. antillarum, C. betulae, C. cinchonensis
and C. phaseoliformis. On account of the morphological features are recognized: C. albescens (= C. betulae, C.
phaseoliformis) and C. cinchonensis. The type of Tremellopsis antillarum is found to be a member of Crepidotus uber but
under the name of C. antillarum s. auct. a distinct taxon has been obscured, which is being described here as C.
pseudoantillarum. Descriptions, illustrations of microscopic features and discussions are provided.
Key words: Crepidotaceae, taxonomy, tropical fungi, wood-inhabiting fungi
Article Information
Received 6 June 2007
Accepted 19 January 2008
Published online 30 September 2008
*Corresponding author: V.M. Bandala; e-mail: victor.bandala@inecol.edu.mx
Introduction
There has been an increment in studying
the macrofungi of Central and South America
(Capelari et al., 2006; Lechner et al., 2006;
Ovrebo and Baroni, 2007; Ortiz-Santara et al.,
2007). In this paper we report new records and
new species of Crepidotus from Mexico and
Coast Rica. Crepidotus includes several species
of lamellate, often sessile, small, brown-spored
mushrooms that constitute an important
component in the community of forest sapro-
trophic fungi. They occur in a wide variety of
ecosystems normally colonizing small plant
debris and fallen wood. Such habits could be
the reason for the worldwide distribution of the
genus and perhaps the patterns of occurrence
currently recorded for the species, in part being
influenced by the local ecological conditions,
rather depend on selected sampling areas (or
intensity of explorations). A small group of
American species have been well documented
(Hesler and Smith, 1965; Singer, 1973) with
additional information on variation of taxono-
mically important morphocharacters, and their
taxonomic circumscription and geographic
occurrence (in some cases embracing far-off
points) is reasonably well supported (Horak,
1964; Singer, 1973; Bigelow, 1980; Luther and
Redhead, 1981; Redhead, 1984; Nordstein,
1990; Pereira, 1990; Senn-Irlet, 1995a; Astier,
1998; Senn-Irlet and De Meijer, 1998; Bandala
et al., 1999, 2006, 2008; Bandala and Montoya,
2000a,b, 2004; Krisai-Greilhuber et al., 2002;
Ripková et al., 2005). While few species are
recognized to have a rather widespread distribu-
tion [e.g. C. applanatus (Pers.) P. Kumm, C.
epibryus (Fr.) Quél. or C. cinnabarinus Peck]
(Pilát, 1948; Hesler and Smith, 1965; Luther
and Redhead, 1981; Senn-Irlet, 1995a; Bandala
et al., 1999), most representatives (including
several taxa currently known only by their
respective diagnoses) display an apparently
restricted or fragmentary distribution. Several
species described from both hemispheres, have
been recorded in a variety of types of
vegetation in Mexico (Bandala et al., 1999;
Bandala and Montoya, 2000a,b, 2004; Krisai-
Greilhuber et al., 2002). Type studies of
phenotypically similar Crepidotus species
describeed from Mexico (Bandala et al., 1999,
2006; Bandala and Montoya, 2000a,b, 2004),

10
revealed that there are eight Mexican species
that currently show an apparent endemism
(Singer, 1957, 1973), excluding C. rubrovinosus
Bandala, Montoya & E. Horak (2006), recently
found also in Central America and not treated
here. In Costa Rica, a single sample of C.
calolepis subsp. polycistis Singer, was gathered
during 1925-1926 by P.C. Standley and J.
Valerio in El Cerro de Las Vueltas (San José)
(Singer, 1973).
During ongoing revisions of Crepidotus
(Bandala et al. 2008; Bandala and Montoya,
2008), we studied some collections from
Mexico and Costa Rica that represent new
species and new records related to the group of
smooth-spored taxa with gelatinized, clamped
hyphae that cluster around C. albescens
(Murrill) Redhead. Besides the opportunity to
give information about their ranges of extension,
the comparative study of the samples with the
reexamination of type specimens revealed
interesting information to support the new
species and to provide additional data for the
taxonomic status of some type collections.
Materials and methods
Macrocharacters were observed on fresh
basidiomes collected in Mexico and Costa
Rica. Specimens from Santuario del Bosque de
Niebla (a cloud forest adjacent to the Instituto
de Ecología A.C. at Xalapa) were collected in
monitored sites (cf. Bandala et al., 2006).
Colour codes in descriptions refer either to
Kornerup and Wanscher (1967, e.g. 2A2–3) or
to Munsell (1994, e.g. 2.5Y 8/2–3). Methods
employed in the microscopic analysis of
specimens, including basidiospore measure-
ments and their statistics, SEM and symbols,
are the same as those used by Bandala et al.
(1999, 2006) and Bandala and Montoya (2000a,
2004). Photographs of microscopic features
were taken from hand sections of revived
tissues mounted in 3% KOH or Congo Red 1%
aqueous solution and observed on a microscope
equipped with a digital camera. Herbarium
acronyms are according to Holmgren et al.
(1990).
Results
The Tremellopsis antillarum Pat. type
specimen, Duss s.n. from Guadaloupe, as
already noted also by Hesler and Smith (1965),
Horak (1968) and Singer (1947), is in poor
condition of preservation that prevents making
an appropriate study. Data introduced by this
latter author suggest that the microscopic
information provided in his monograph is a
composite description resulted by including his
collections from Florida, as well as the type
specimen of Crepidotus cinchonensis Murrill
(1913) from Jamaica. Following Singer (1947),
the so-called C. “antillarum” was therefore a
taxon microscopically characterized by smooth,
ellipsoid (“…with the inner side flatter…”)
basidiospores, clamped hyphae, gelatinous
hyphae in the pileus trama and clavate or at
times subcapitate cheilocystidia (Hesler and
Smith, 1965; Horak, 1968; Singer, 1973; Pegler,
1983; Senn-Irlet and De Meijer, 1998). Our
reexamination of Tremellopsis antillarum type
collection Duss s.n. revealed, however, informa-
tion that agrees in part with the aforementioned
authors, especially with observations by Horak
(1968) regarding the basidiospore features (see
below). Our results after studying the type of T.
antillarum and collections from Costa Rica and
Mexico, compared with published descriptions
of all phenotypically related taxa, led to
conclude that: i) the specimen of Duss s.n. falls
within the range of variation recorded for C.
uber (Berk. & M.A. Curt.) Sacc. and perhaps it
represents a sample of this species, and ii) we
recognized two undescribed species (one of
them obscured under the name C.” antillarum”
s. auct.) which share taxonomically important
and unique set of striking features with the
group of taxa around C. albescens, i.e.
ellipsoid-reniform basidiospores, clamped
hyphae, and gelatinized tissues. Additionally,
on the basis of microscopic characters shown
by the collection of Duss s.n. (clampless
hyphae, relatively small spores) and the type
specimen of Crepidotus cinchonensis (clamped
hyphae, broad spores), they could hardly be
considered to belong to the same taxon. Type
studies, descriptions and discussions on these
taxa are presented below in three sections, one
includes the reevaluation of Tremellopsis
antillarum, other the description of the two
new species, and the third, the study of
collections related to C. albescens.

Fungal Diversity
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Taxonomy
A. Reevaluation of Tremellopsis antillarum
Tremellopsis antillarum Pat., in Duss, Enum.
Champ. Guad. p.13 (1903).
(Figs 1a, 2-3a-b)
= Crepidotus antillarum (Pat.) Singer,
Lilloa 13: 62 (1947)
Material examined: GUADALOUPE. Matouba,
no date, Duss s.n. (Holotype, FH, Patouilliard
Herbarium No. 224)
Tremellopsis Pat. (in Duss op. cit.) was
conceived as a “gélatineux-tremelloïde” genus
with “…basides claviformes, non septées,
portant 2-4 stérigmates… cystides nulles…
spores ocracées”. Macroscopic data in the
protologue for the single species recognized by
N.T. Patouilliard (T. antillarum) are the
following: “…plante de 1-2 centim. de haut
sur 2-3 de large… réceptacle formant une
masse gélatineuse, composée de feuillets
dressés, chiffonnés, entiers ou lobés, plus ou
moins rameux, rayonnants autour d´un point
central, sessile ou élevé sur une portion
stiptiforme trés courte. Feuillets grisâtres,
devenant roux-ocracés, peu épais…”.
Microscopic features seen in the holotype are:
basidiospores 6.5-9(-9.5) × (4-)4.5-6 µm,
x
=
7.7 × 5.1 µm, Q = 1.50, ellipsoid, often weakly
attenuated towards apex, then more or less
amygdaliform on side view, smooth, thick-
walled (≤ 0.5µm wide), pale yellowish-brown,
under SEM smooth and lacking germ pore
(Figs 1a and 3a-b). Tissues hardly revived with
KOH but both pileus and hymenophoral
tramae consist of slightly gelatinized, hyaline,
clampless hyphae (at least most septa recover-
ed). Basidia, cheilocystidia and pileipellis not
recovered (in protologue the basidia were
reported 30-35 × 10 µm).
Notes: Judging by its present, rather
papyraceous consistency and appearing strongly
pressed, probably the material of Duss s.n. was
wet or overmature when collected, and consi-
dering its gelatinous nature, it practically collapsed
after drying. Data provided by Duss (1903),
indeed, rather suggest the inappropriate condition
of his collection when gathered, perhaps the
reason why N.T. Patouilliard related it to
tremelloid forms. The protologue does not
mention the presence or absence of clamps but it
specifies the lack of cystidia. Lamellae edges
can hardly be analyzed and no more than the
basidiospores and some of the features of
certain tissues can be recovered. Singer (1947)
recognized the taxon as Crepidotus especially
pointing out the macromorphology in combi-
nation with basidiospore features seen in the
holotype. The basidiospores in fact were the
only microscopic structure clearly indicated by
Singer to have been observed in the holotype
[with regard to basidia in 1973: 429, he wrote:
“…The type of C. antillarum is said to be 2-4
spored (which I could not verify any more)…”].
His previous information (Singer 1947) “…
derived from the type specimen in the
Patouilliard herbarium … secured by studying
the type of C. cinchonensis and some fresh
material collected by myself in South
Florida…”, denotes that the author provided a
composite description. He concluded that
“…summing up the data obtained from these three
sources, one will attribute to C. antillarum…
spores (8-)8.2-10.5(-11) × 5.2-6.8 µm, smooth…
ellipsoid, with the inner side flatter… basidia
(16-)20-37 × (5-)7.5-10.3 µm, either 2-spored or
4-spored (the Florida collection… was entirely
bisporous; the other collections are predominantly
tetrasporous)…; cheilocystidia ventricose… the
upper ventricosity often appearing as if the
cheilocystidia were capitate… 33-51 × 5.5-10.3
µm…, hyaline hyphae with clamp connections…
trama of the pileus rather thin, subgelatinous…”.
A similar concept was maintained until his work
of 1973. One of his collections from Mexico
(Singer M 8093) studied here fits indeed that
concept. Hesler and Smith (1965) followed Singer
providing a composite description also with C.
cinchonensis as a synonym. These authors as
well as Horak (1968), stressed the bad state of
the holotype of Tremellopsis antillarum, Horak
in fact, underlined not having found cheilo-
cystidia, hence referring to information by
Singer (1947) and Hesler and Smith (1965) for
the interpretation of the character. We share
Horak’s (1968) opinion that in the material of
Duss s.n. it was not possible to verify the
presence of cheilocystidia (although the proto-
logue indicates indeed the absence of cystidia).
The pattern of size and shape of the basidio-
spores observed in this revision also agrees with
the results of Horak (op. cit.) who showed that
the specimen of Duss s.n. is characterized by its
moderately small-sized (7.5-9 × 5-6 µm),
ellipsoid to amygdaliform basidiospores. Our

12
Fig. 1. a. Tremellopsis antillarum. Basidiospores (from holotype). b. Crepidotus cinchonensis (from holotype). Bars =
10 µm.
Fig. 2. Scatter plot of basidiospore size (means) in
collections of Tremellopsis antillarum (×, holotype),
Crepidotus albescens (□), C. cinchonensis (+, holotype),
C. herrerae (U), and C. pseudoantillarum ({).
type study did not reveal clearly the presence of
clamps at least in many accurately recovered
septa.
On account of the ellipsoid to amygda-
liform, moderately small-sized basidiospores,
gelatinized, clampless hyphae, in combination
with the relatively small, grayish basidiome, the
specimen of Duss s.n. that supports Tremellop-
sis antillarum, in our opinion, represents a
member of C. uber (for description cf. Singer,
1973; Senn-Irlet and De Meijer, 1998). The
taxonomic implication of all this is the existence,
in fact, of a distinct taxon represented by
specimens inhabiting fallen wood in tropical or
subtropical forest from Mexico, the Caribbean
and Central and South America. This taxon
exhibits just the set of characters fixed until now
for what has been called C. “antillarum” after
Singer (1947) (Hesler and Smith, 1965; Horak,
1968; Singer, 1973; Pegler, 1983; Senn-Irlet and
De Meijer, 1998) but it excludes Tremellopsis
antillarum as described above. We interpret that
the collections that Singer (1947) treated under
C. “antillarum” are not the same as Tremellopsis
antillarum, since the set of characters that
include medium to large-sized, ellipsoid to
oblong and more or less kidney-like or bean-like
shaped (due to a flattening or a weak curving
inward in the adaxial face) basidiospores,
cheilocystidia mostly clavate, pileipellis bearing
somewhat undifferentiated terminal elements,
and tissues with gelatinized, clamped hyphae
(Figs 4-6f-g) are features that taxonomically
show similarity to the group of species near C.
albescens rather than to Tremellopsis antillarum
or even Crepidotus cinchonensis. We found that
C. cinchonensis and Tremellopsis antillarum are
only superficially similar based on macroscopic
features. Hand sections of the holotype of C.
cinchonensis (JAMAICA. Cinchona, wet moun-
tainous region, 25 December 1908-8 January
1909, W.A. Murrill & E.L. Murrill 610, NY)
revived with difficulty in KOH preventing us
from developing an appropriate evaluation of
gelatinized layers in pileus and lamellae tramae
(cf. e.g. key in Hesler and Smith 1965). How-
ever, it presents gelatinized, clamped hyphae
that more or less recall puzzle-like elements,
therefore it differs from Tremellopsis antillarum
but resembles members close to C. albescens
(like C. “antillarum” s. auct.). Crepidotus cincho-
nensis is also distinguished by its pileipellis,
apparently a cutis, composed of undifferentiated
terminal elements, basidia 23-35 × 7-11 µm,
clavate, 4-spored, clamped, and basidiospores
(7.5-)8-10 × 5-6.5 µm (
x
= 8.9 × 5.8 µm, Q =
1.54), ellipsoid, mostly without an adaxial
concavity (so appearing not reniform)(Figs 1b-3

Fungal Diversity
13
Fig. 3. Scanning electron micrographs of Crepidotus basidiospores. a-b. Tremellopsis antillarum (from holotype). c-d.
Crepidotus cinchonensis (from holotype). Bar: 1 µm, except b = 2 µm.
c-d). L.R. Hesler wrote in a note of revision
accompanying the holotype (indeed the same
data later published by Hesler and Smith, 1965)
that most cheilocystidia are collapsed against
the gill edges. In fact, the cheilocystidia revived
with difficulty and prevent us to describe with
confidence the shape of individual cells, to have
an appropriate interpretation of their pattern of
variation and compare them within the range of
variation of this character shown by collections
of C. “antillarum” s. auct.
In conclusion, C. cinchonensis does not
seem to share unique morphological characters
with the so-called C. “antillarum” or at least the
available data from the holotype do not allow us
to accurately place it within that taxon. For the
time being C. cinchonensis should be kept
separate since it is also fairly different from
Tremellopsis antillarum or even shows a certain
resemblance to C. virgineus Har. Takah.
(Takahashi, 2003). The holotype of Tremellopsis
antillarum strongly resembles members of
Crepidotus uber in having similar basidiospores
(size, shape) and gelatinized, clampless hyphae,
and therefore Tremellopsis antillarum is
interpreted as a later synonym:
Crepidotus uber (Berk. & M.A. Curt.) Sacc.,
Syll. Fung. 5: 878 (1887).
Basionym: Agaricus uber Berk. & M.A. Curt.,
Proc. Amer. Acad. Arts Sc. 4: 117 (1858).
Synonym: Tremellopsis antillarum Pat., in Duss,
Enum. Champ. Guad. p.13 (1903).
= Crepidotus antillarum (Pat.) Singer, Lilloa 13:
62 (1947).
Crepidotus uber is a small, white, gelatinous
fungus inhabiting the tropical and subtropical
forest from the Gulf of Mexico area, Caribbean
and South America (Singer, 1973; Pegler, 1983;
Senn-Irlet and De Meijer, 1998; Bandala and
Montoya, 2002).
On account of the aforementioned infor-
mation, as well as the data obtained from
different examined specimens (from Costa Rica
and Mexico, type specimens supporting species
related to the group of C. albescens), all
compared with published descriptions of C.
“antillarum” s. auct., it is now accepted that
three distinct species can be recognized, two of
them representing undescribed taxa. These three

14
species share a consistent set of characters, i.e.
clamps, gelatinized tissues, ellipsoid, more or
less reniform and smooth basidiospores, and
constitute a group of taxa phenotypically similar
to the species of the C. mollis (Schaeff.) Staude
group which form gelatinized tissues, have
smooth basidiospores but lack clamps. Crepidotus
albescens described from the USA (Murrill,
1916 as Geopetalum; Redhead, 1984) is distin-
guished by the subcylindric to more or less
narrowly lageniform, remarkably elongate
cheilocystidia in combination with a pileipellis
made of more or less filamentous, undifferen-
tiated terminal elements (Figs 6a-e and 9-11).
The two new species differ in having somewhat
large basidiospores and clavate or moderately
capitate cheilocystidia (Figs 2, 4-6f-i and 7-8).
One of these species, which corresponds to what
has been called C. “antillarum” s. auct., is
distinct in that it combines a pileipellis with
undifferentiated terminal elements, while the
other undescribed taxon combines a pileipellis
bearing distinctly versiform (i.e. constrictions,
short outgrowths, contorted), ventricose ter-
minal elements similar to its cheilocystidia. The
three species are described below.
B. Description of new species
Crepidotus pseudoantillarum Bandala, Montoya
& M. Mata, sp. nov. (Figs 2, 4-6f-g & 12a)
MycoBank: 512445
Etymology: referring to a false Tremellopsis anti-
llarum.
Pileus 4-42 mm latus, dimidiatus vel flabellatus,
convexus, albidus, tomentosus vel tomentoso-fibrillosus,
striatulatus, hygrophanous, viscidus. Lamellae subdistantes,
albidae, dein brunneae, marginem fimbriatae. Stipes
primo lateralis, minutus, senectute saepe deest. Contextus
albidus, immutabilis, gelatinosus. Basidiosporae (7-)7.5-
11 × (4-)4.5-5.5(-6.5) µm, ellipsoideae vel subreniformeae,
laevis, ochraceae. Basidia 20-35 × 5-7 µm, clavata,
bispora vel monospora. Cheilocystidia 27-65 × 4-7(-8) ×
(apicem) 6-13(-14) µm, clavata vel clavato-capitata,
hyalinis, gelatinous. Pileipellis ex hyphis hyalinis, cylin-
draceis, laxe intricatis, subtrichodermium vel cutem
formantibus. Tramate pilei et tramate hymenophoralis
gelatinosae. Fibulae praesentes. COSTA RICA. Guana-
caste: Arenal, Volcán Tenorio, Hacienda Montezuma, 5
May 2000, López 1296 (Holotypus, INB; Isotypus
XAL).
Pileus 4-42 mm broad, in young stages
ungulate to more or less campanulate, becoming
convex or almost plano-convex, subcircular or
circular to dimidiate, at times more or less
rounded flabelliform or somewhat petaloid, with
or without a slot in the rear portion (when seen
from the hymenophore), this produces two
short, lobe-like hemispheres, then somewhat
rounded reniform, whitish, whitish-translucent
to pale grayish, brownish in parts by spores
deposit on surface, not or slightly translucent
striate, variably viscid (sticky to the touch), hy-
grophanous, tomentose to tomentose-fibrillose,
almost minutely villose near point of attach-
ment; margin incurved, later inflexed to
moderately straight, thin, weakly tomentose-
fimbriate to glabrous, wavy (mainly when fully
expanded), slightly exceeding the lamellae.
Lamellae whitish becoming pale brown, some
with pinkish shades, with whitish, fimbriate,
somewhat irregular edges which are somewhat
elastic; adnexed to narrowly adnate, some
weakly subdecurrent, concurrent to a lateral
point, subdistant, broad (≤ 4 mm broad), more
or less ventricose, lamellulae 3-4 different
length. Stipe in young stages lateral, rudimen-
tary (< 2 mm long.), whitish, pruinose, with age
absent or persisting as a lateral, glabrous knob
(when seen from the hymenophore) but the
pileus is directly attached laterally or almost
dorsally to the substratum; basal mycelium
white, present or absent. Context watery,
whitish, thin to more or less thick from center
backwards (2-5 mm thick), hygrophanous then
opaque, soft, elastic, unchanging on exposure.
Odor and taste not distinctive.
Basidiospores (7-)7.5-11 × (4-)4.5-5.5(-
6.5) µm,
x
= 8.2–9.9 × 4.8-5.7 µm, Q = 1.7-
1.79, oblong to ellipsoid or moderately narrowly
ellipsoid, weakly applanate or depressed adax-
ially then slightly reniform, apiculus very small,
apex weakly tapered but rounded, wall at times
bearing a discontinuity resembling a germ pore,
smooth, thin- to slightly thick-walled (≤ 0.5 µm
thick), yellow to pale yellowish-brown; under
SEM smooth and lacking germ pore. Basidia
20-35 × 5-7 µm, 2-spored, often monosporic,
clavate, thin-walled, hyaline, clamped. Pleuro-
cystidia absent. Cheilocystidia 27-65 × 4-7 (-8)
µm, numerous, narrowly clavate to subclavate,
often narrowly utriform, apex rounded or sub-
capitate 6-13 (-14) µm wide, occasionally sub-
cylindric-capitate, straight or somewhat sinuous,
hyaline, thin-walled, clamped, gelatinized, pro-
ducing a more or less dense, refringent layer on
lamellae edge.Pileipellis a loose trichoderm or a

Fungal Diversity
15
Fig. 4. Crepidotus pseudoantillarum (from holotype). a. Basidiospores. b. Pileus trama hyphae. c. Cheilocystidia. d.
Basidia e. Pileipellis. Bars: a, c & d = 10 µm, b & e = 20 µm.

16
Fig. 5. Crepidotus pseudoantillarum (from holotype). a. Tangential section of pileipellis. b. Cheilocystidia. Bars: a =
20 µm, b = 10 µm.
transition to a loose cutis, composed of cylin-
dric, interwoven hyphae 5-8(-11) µm wide,
hyaline, simple or bifurcate, clamped, thin- or
slightly thick-walled (≤ 0.5 µm thick), smooth,
with a variable number of undifferentiated
(rarely very narrowly sublageniform or elongate
-subcapitate), straight terminal elements, the
layer is ungelatinized and variable in depth and
in density of hyphae, at times in some areas
even of a single specimen the ascendant hyphae
are more tightly packed and projecting or in
other areas these hyphae are more postrated.
Pileus trama (in tangential section) differen-
tiated in two layers, one beneath pileipellis,
gelatinized, refringent, variable in depth,
composed of more or less filamentous hyphae 2-
5 µm wide, hyaline, thin-walled, smooth, some
occasionally obscurely punctate, somewhat flex-
uous, more or less radially oriented and loosely
interwoven; below that layer is a distinctive
moderately compact, gelatinized but not refrin-
gent stratum comprising most of the pileus
context and composed of colorless, thin-walled,
subcylindric to subventricose, simple, bifurcate
or occasionally ramified hyphae (3-)4-15(-17)
µm wide, often short-bifurcate, somewhat
irregularly arranged forming a puzzle-like
structure. Hymenophoral trama with a medio-
stratum, irregular to subregular, composed of
hyphae similar to those from lower part of
pileus trama; laterostrata refringent, gelatinized,
composed of filamentous, colorless to pale
yellowish, thin-walled hyphae 2-5 µm wide,
loosely and more or less divergently arranged.
Clamp connections present in all tissues.
Habitat: Gregarious, on decaying branches
or wood, in tropical and subtropical cloud forest,
at 800-1700 m alt.
Known distribution: Bermuda, Brazil,
Colombia, Costa Rica, Cuba, Jamaica, Martini-
que, Mexico.
Material examined: COSTA RICA: Guanacaste:
Arenal, P.N. Volcán Tenorio, Hacienda Montezuma, 5
May 2000, López 1296 (Holotype, INB; Isotype XAL).
MEXICO. Chiapas: Mpio. Ocozocuautla, Reserva
Laguna Bélgica, 5 September 2006, Bandala 4211 (XAL).
Veracruz: 7 km S of Montepio, Estación Biológica de
Los Tuxtlas, 20 May 1969, Singer M 8093 (F, as
Crepidotus antillarum). Mpio. Rafael Lucio, Sta.
Bárbara Farm, 18 February 1986, Bandala 735; Mpio.
Apazapan, Apazapan, 7 August 1994, Leal 458 (XAL).
Other material examined: CUBA. Prov. Pinar del
Río, Candelaria Co., Reserva Sierra del Rosario, 9
December 1994, Bandala 2720 (XAL). JAMAICA.
Marce's Gap, mountainous region, 29 December 1908-2
January 1909, Murrill & Murrill 686 (NY, as Crepidotus
cinchonensis).
Notes: Distinctive features that separate
C. pseudoantillarum from other white,
gelatinized, clamped, smooth-spored species
are the clavate to more or less subcapitate
cheilocystidia and a pileipellis composed of
undifferentiated terminal elements. This taxon
encompasses the attributes of what Singer
(1947) understood and circumscribed as C.
“antillarum”, a concept later extended in
subsequent literature (for further information
please refer to the discussion under Tremel-
lopsis antillarum above). Crepidotus pseudo-
antillarum seems to enclose some variants
producing different numbers of spores per
basidium. Collections examined here often
presented 2-spored or monosporic basidia; the
taxon is reported to include specimens (1-)2(3-)-

Fungal Diversity
17
Fig. 6. Scanning electron micrographs of Crepidotus basidiospores. a-e. C. albescens (a-b: from holotype; c: Kelly 158,
holotype of C. phaseoliformis; d-e: Earle 241, holotype of C. betulae). f-g. C. pseudoantillarum (from holotype). h-i. C.
herrerae (from holotype). Bars: a-e = 1 µm, f-i = 2 µm.
spored, 2-4-spored or 4-spored basidia (Singer,
1947, 1973; Pegler, 1983; Senn-Irlet and De
Meijer, 1998; all as C. antillarum). The
gelatinous layer resting just beneath the
pileipellis can be thick and refringent in fresh
or well revived specimens, although in some
cases it is weakly refringent but differentiated
(as in specimen Bandala 4211) or it can be
very compact and hence apparently absent
(Bandala 735, 2720), in both later situations
the pileipellis hyphae rather rest on the pileus
trama. At times some lamellae (even of a same
specimen) in tangential section show a
variation in the depth of the gelatinized
laterostrata, being more refractive in some than
in others. Singer (1973) observed something
similar among his specimens. Pegler (1983)
reported the subhymenial layer as being poorly
developed and the hymenophoral trama
subgelatinized, not mentioning the pileus trama
characteristics. Senn-Irlet and De Meijer
(1998) described a distinct gelatinous layer
behind the subhymenium and jigsaw-like cells
of the pileus trama. Our study of specimens of
C. pseudoantillarum and other related members
revealed that a well preserved sample from
which a good revived tangential section can be
obtained, allows to observe the disposition of

18
the gelatinized layers, one of them located just
beneath the pileipellis, another just below the
lower part of the context (i.e. the continuation
of the subhymenium), and finally, the
laterostrata in the lamellae (cf. Fig. 11a-b) (at
times producing a dense, gelatinized lamellae
tip where the cheilocystidia are immersed).
Such layers, even in the same sample, vary to a
greater or lesser degree both in depth and
refraction, and consequently one or more layers
can be better defined. A similar variation, more
dependent on the influence of weather conditions
and later drying of the material, is, in fact,
observed also among samples representing
different species of Crepidotus that form
gelatinized tissues (Singer, 1973; Nordstein,
1990; Senn-Irlet, 1995a; Bandala and Montoya,
2004; Gonou-Zagou and Delivorias, 2005).
Apart from the diagnostic set of characters
of C. pseudoantillarum the size of the basidio-
spores can be indicative also of taxonomic
differences. Fig. 2 depicts the mean values of
length and width of the basidiospores based on
available collections of the three species
studied in this group. Comparing these values,
the specimens of C. pseudoantillarum show a
different range in relation to that observed on
C. albescens and the next new species treated
(see below). This later taxon presented larger
basidiospores, with a range above that displayed
by C. pseudoantillarum which at the same
time, showed a larger basidiospore range than
C. albescens. Collections of C. albescens
perhaps produce small-sized basidiospores due
to the consistent presence of tetrasporic basidia,
in comparison with the other two species which
possess bisporic or monosporic basidia. Further
confirmation of the taxonomic value of the
basidiospore size will be achieved when the
number of collections be increased to corrobo-
rate if those patterns are effectively consistent.
It is interesting to comment additionally
that a similar situation in the size of the
basidiospores is well known among bisporic
and tetrasporic forms of Simocybe (Senn-Irlet,
1995b), the sister genus of Crepidotus (Moser,
1983; Singer, 1986; Moncalvo et al., 2002; Aime
et al., 2005). The limits between Simocybe and
Crepidotus have been (until recently) defined
artificially to some extent by having been based
exclusively on a reduced number of species of
each genus for comparison. It is not surprising
that macroscopy has been used as the first
criterion of segregation between a more consis-
tently stipitate taxon (Simocybe) and another
apparently sessile (Crepidotus). Through C.
pseudoantillarum and allied species as well as
other lineages, Crepidotus not only shares with
Simocybe morphologically similar spores
(yellowish to yellowish-brown or brownish,
smooth, variably reniform, lacking germ pore)
(Pegler and Young, 1975; Senn-Irlet, 1995b)
but also anatomical details of the pileipellis
(more than with Agrocybe and other Bolbitia-
ceae which differ in having a cuticle in a
palisadoderm, Watling, 1965; Watling and
Largent, 1976). The core species of Simocybe,
that includes European species like S. centun-
culus (Fr.) P. Karst. and S. sumptuosa (P.D.
Orton) Singer, or American members like S.
alachuana (Murrill) Singer or S. atomacea
(Murrill) Singer among others, certainly have a
pileipellis with a closer arrangement pattern,
bearing more defined cystidia-like terminal
elements and hence appearing more tricho-
dermoid. However, other members like S.
iberica G. Moreno & Esteve-Rav. and S.
quebecensis Redhead & Cauchon possess a
pileipellis with a looser or somewhat entangled
arrangement, composed of interwoven, more or
less filamentous elements, rather radially
oriented, hence appearing in parts as a loose
cutis or a loose trichodermoid pileipellis
(Redhead and Cauchon, 1989; Moreno and
Esteve-Raventós, 1990; Senn-Irlet, 1995b;
pers. obs.). The pileipellis in both cases seems
to be comparable (if not identical) with that
found in several Crepidotus species, e.g. C.
eucalyptinus Maire & Malençon, C. lepton
(Berk.) Sacc., C. pezizula (Berk. & Broome)
Sacc., C. variabilis (Pers.) P. Kumm., among
others (Malençon and Bertault, 1975; Pegler,
1986; Senn-Irlet, 1995a; pers. obs.). In cases
such as Simocybe fulvifibrillosa (Murrill)
Singer, S. ovalis Singer or S. coroicensis Singer
(Singer, 1973) a pileipellis like that of many
Crepidotus, i.e. with more prostrate, relatively
compact hyphae and with scattered, not neces-
sarily differentiated terminal elements, can be
found. Even in species like C. cristulatus
Singer, C. rubriceps Singer and the other new
species herein proposed (see below), the pilei-
pellis has more defined terminal elements,
resembling cystidia-like structures in compari-

Fungal Diversity
19
son with the core species of Simocybe. In very
young stages Crepidotus possesses an almost
tiny stipe, which only in a few species becomes
clearly visible (elongate) with age (Horak,
1977; Bigelow, 1980; Aime et al., 2002). In
most species it is reduced and is perhaps not in
the form of a centrally attached, elongate,
single structure as commonly found in Simocybe
but lateral or excentric (a short, subcylindric or
swollen knob), often appressed against the
pileus margin (occasionally free), forming
together a point of attachment to the
substratum (seen from the hymenophore). The
placement of pleurotoid forms in Simocybe is
firstly attributable to the presence of a reduced
stipe and secondly to the pileipellis (when the
basidiospores are not reniform), while inclu-
sion of stipitate forms in Crepidotus is based
mainly on the combination of the basidiospores
being ornamented (or if smooth, not being reni-
form) together with other microscopic characters.
Hesler and Smith (1965: 9) already suggested
“… Although of minor importance as a
taxonomic feature, the pseudostipe may have
ontogenetic significance which indicates a
phylogenetic connection from normally stipi-
tate ancestors…”. Molecular data add evidence
to support the close relationship between
Simocybe and Crepidotus placing the lineage of
C. pseudoantillarum (with C. betulae, i.e. C.
albescens, see above), in resulting trees, at the
base of the Crepidotus clade and closely related
to the grouping of Simocybe species (Aime et
al., 2005). The variation in characters
represented by members of Crepidotus and
Simocybe, both within and between the genera
(pileus fibrillose or somewhat pruinose, stipe
well defined and elongate or defined but
reduced; basidiospores smooth, ellipsoid or
ovoid, more or less reniform or not; pileipellis
variably trichodermoid or in cutis, loose or not)
would indicate that Simocybe differs by the
abundant pileo- and caulocystidia, cheilocys-
tidia more typically capitate and that several
species have olivaceous pileus coloration.
Delimitation of both genera would be based
then on such subtle morphological differences
exclusively. We share Aime’s et al. (2005)
opinion that the microscopic characters offer a
more natural distinction but all the aforemen-
tioned information on such combination of
characters found among representtatives of
Simocybe and Crepidotus are perhaps more
proper of an assemblage of taxa sharing a very
close common ancestry than to interpret two
discrete entities.
Crepidotus herrerae Bandala & Montoya, sp.
nov. (Figs 2, 6h-i-8 & 12b)
MycoBank: 512446
Etymology: in honor of Dr. Teófilo Herrera Prof.
emeritus of the UNAM for his extensive work on the
fleshy fungi of Mexico over the past fifty years, which
have facilitated the development of taxonomic mycology
in Mexico and inspired many colleagues and students.
Pileus (2-)5-32 mm latus, subcampanu-
latus vel flabellatus, convexus dein planocon-
vexus, albidus vel sordido-albidus, tomentosus
vel tomentoso-granulosus, striatulatus, hygro-
phanous, viscidus. Lamellae subdistantes, albi-
dae dein ochraceobrunneae, marginem fimbria-
tae. Stipes primo lateralis, minutus, senectute
saepe deest. Contextus albidus, immutabilis,
gelatinosus. Basidiosporae (8-)8.5-10.5(-11) ×
5-6(-6.5) µm, ellipsoideae vel subovoideae vel
subreniformeae, laevis, ochraceae. Basidia 25-
30 × 5-7 µm, clavata, bispora vel monospora.
Cheilocystidia 30-57(-68) × (3-)4-7(-8) ×
(apicem) (5-)6-16 µm, clavata vel clavato-
capitata, saepe irregularis, contortis, hyalinis,
gelatinosus. Pileipellis ex hyphis hyalinis,
claviformis, 29-55(-62) × 5-17 µm, cheilocys-
tidia recordatio, trichodermium intermittere
formantibus. Tramate pilei et tramate hymeno-
phoralis gelatinosae. Fibulae praesentes.
MEXICO. Veracruz: Instituo de Ecologia,
Santuario del Bosque de Niebla, 30 March
2004, Bandala 3895 (Holotypus, XAL).
Pileus (2-)5-32 mm broad, when young
umbonate near point of attachment then some-
what campanulate, becoming convex or plano-
convex, at times spathulate when young, later
subcircular, at times more or less rounded flabel-
liform or somewhat reniform, white or whitish,
becoming pale-yellowish (2.5Y 8/2-3; near
2A2-3) with shades of pale yellowish-brown
(2.5Y 7/3-4) or pale-grayish or darker (more or
less 10YR 6-7/4), if wet almost entirely grayish
and more or less translucent, then translucent
striate in most part of disc, viscid when young,
becoming slightly lubricous (weakly sticky to
the touch) to dry, hygrophanous, at first more or
less tomentose-granulose, becoming tomentose
to glabrous, in young stages tomentose-villose
near point of attachment; margin incurved, later

20
Fig. 7. Crepidotus herrerae (from holotype). a. Basidiospores. b. Basidia. c. Cheilocystidia. d. Terminal elements of
pileipellis. e. Pileipellis. Bars: a-d = 10 µm, e = 20 µm.

Fungal Diversity
21
Fig. 8. Crepidotus herrerae (from holotype). a. Tangential section of pileipellis. b. Terminal elements of pileipellis. c.
Pileipellis and refringent, gelatinized layer of context (tangential section). d. Cheilocystidia. Bars: a = 25 µm, b & d = 10
µm, c = 50 µm.
straight, smooth, translucent striate or not; lat-
erally attached to substrate. Lamellae whitish,
becoming faintly brownish (10YR 7/3-4),
yellowish-brown to pale brown (10 YR 6/6) or
grayish-brown (more or less 10YR 5-6/4), some
with pinkish shades, with whitish, fimbriate
edges which are somewhat elastic; adnexed to
narrowly adnate, some weakly subdecurrent,
concurrent to a lateral point, subclose to subdis-
tant, broad (≤ 3 mm broad), more or less
ventricose, at times exceeding the pileus margin,
lamellulae up to 3 different lengths. Stipe in
young stages lateral, rudimentary (up to 2 mm
long.), pruinose, with age absent or persisting as
a lateral, cylindric, whitish, glabrous knob (when
seen from the hymenophore) but the pileus is
directly attached to the substratum; basal myce-
lium white when present. Context white, thin (<
1 mm thick), hygrophanous, soft, gelatinous,
elastic near pileus surface, unchanging on
exposure. Odor and taste not distinctive. Spore
print (seen on pileus surface) yellowish-brown
to dark brownish (near 10YR 5-6/6).
Basidiospores (8-)8.5-10.5(-11) × 5-6(-
6.5) µm,
x
= 9.4–9.8 × 5.8–5.9 µm, Q = 1.62-
1.66, oblong or ellipsoid, some subovoid in
dorso-ventral view, at times weakly applanate or
depressed adaxially then slightly reniform, with
rounded extremes, apiculus inconspicuous, wall
often bearing a discontinuity resembling a germ
pore, smooth, thick-walled (< 1 µm wide),
yellowish to pale yellowish-brown, under SEM
smooth and lacking germ pore. Basidia 25-30 ×
5-7 µm, 2-spored, often monosporic, rarely 4-

22
Fig. 9. Crepidotus albescens. a. Basidiospores. b. Cheilocystidia (from holotype). c. Cheilocystidia. d. Basidiospores
(Earle 241, holotype of C. betulae). e. Basidiospores (Kelly 158, holotype of C. phaseoliformis). Bars = 10 µm.
spored, subclavate to subcylindric, thin-walled,
hyaline, clamped. Pleurocystidia absent. Cheilo-
cystidia 30-57(-68) × (3-)4-7(-8) µm, numer-
ous, narrowly clavate to subclavate, at times
narrowly utriform, often with constrictions or
short outgrowths, then somewhat irregular in
form, occasionally septate, apex rounded or
subcapitate (5-)6-16 µm wide, hyaline, at times
with a yellowish content, thin-walled, clamped,
gelatinized. Pileipellis an interrupted tricho-

Fungal Diversity
23
derm, composed of clusters of terminal elements
which are colorless (occasionally intermixed
pale yellowish), thin-walled, clavate, narrowly
utriform, narrowly lageniform, or rarely
subcylindric, apically rounded, 29-55 (-62) × 5-
17 µm, often contorted or with constrictions,
with short outgrowths or bifurcate, then more or
less irregular in form (more or less resembling
the cheilocystidia), at times loosely arranged or
almost postrated and then in a transition
between a loose cutis and a trichoderm; near
pileus trama the hyphae are 2-9 µm wide,
interwoven, more or less radially oriented,
hyaline, thin-walled, forming an undifferen-
tiated, ungelatinized, thin layer. Pileus trama (in
tangential section) differentiated in two layers,
one beneath pileipellis, gelatinized, refringent,
variable in width, composed of more or less
filamentous hyphae (1-)2-3(-5) µm wide, hyaline,
thin-walled, smooth, some occasionally obscurely
punctate, more or less radially oriented and
loosely interwoven, some oleiferous-like hyphae
present; just downwards with a moderately
compact to loose, gelatinized but not refringent
tissue comprising most of the pileus context,
composed of colorless, thin-walled, subcylindric
to subventricose, simple, bifurcate or occasion-
ally ramified hyphae (3-)5-20 µm wide, often
short, somewhat irregularly arranged forming a
puzzle-like structure. Hymenophoral trama with
a mediostratum, irregular, composed of hyphae
similar to those from lower part of pileus trama;
laterostrata refringent, gelatinized, composed of
filamentous, colorless to pale yellowish, thin-
walled hyphae (1-)2-5 µm wide, loosely and more
or less divergently arranged. Clamp connections
present in all tissues.
Habitat: Gregarious, on a decaying liana,
and branches, in subtropical cloud forest, at 1300
m alt.
Known distribution: Mexico.
Material examined: MEXICO. Veracruz: Mpio.
Xalapa, Instituto de Ecología, Santuario del Bosque de
Niebla, 1 July 2003, Bandala 3775; 30 March 2004,
Bandala 3895 (Holotype); October 19, 2005, Jarvio 2477
(all at XAL).
Notes: Crepidotus herrerae is a striking
white, clamped, smooth-spored species related
to C. albescens and C. pseudoantillarum (both
treated here). It differs in the cheilocystidia and
terminal elements of the pileipellis, both
clavate and remarkably lobed, angled or bifur-
cate (due to constrictions or short outgrowths).
Crepidotus herrerae also seems to have bigger
spores in comparison with these two species
(Fig. 2). Cheilocystidia somewhat similar to
those of C. herrerae, i.e. more or less
versiform-clavate (seen in outline), are also
present in other members of Crepidotus (e.g. C.
croceitinctus Peck, C. macedonicus Pilát or
even C. variabilis) but members combining
cheilocystidia and pileipellis terminal cells
similar in shape are very rare. In some stages of
development the basidiomes of C. herrerae
could superficially recall specimens of C.
applanatus, another white taxon recognized by
different microscopical features (globose,
ornamented basidiospores, lack of gelatinized
tissues) (Josserand, 1937; Nordstein, 1990;
Senn-Irlet, 1995a).
C. Description and new records of Crepi-
dotus albescens
Crepidotus albescens (Murrill) Redhead,
Sydowia 37: 255 (1984)
(Figs 2, 6a-e & 9-11)
Basionym: Geopetalum albescens Murrill, N. Am.
Fl. 9: 299 (1916).
Synonyms: Crepidotus betulae Murrill, N. Am. Fl.
10: 151 (1917).
= C. phaseoliformis Hesler & A.H. Sm., N. Am.
Sp. Crep., p. 92 (1965).
Pileus 5-70 mm broad, more or less
ungulate in young stages, becoming convex or
plano-convex, subcircular or circular to dimidi-
ate or more or less rounded flabelliform, white
or whitish to pale grayish, not or translucent
striate, somewhat viscid (sticky to the touch),
hygrophanous, tomentose or slightly tomentose-
fibrillose; margin inflexed. Lamellae pale brown
to grayish-brown with whitish, fimbriate edges
which are somewhat elastic; adnexed to narrow-
ly adnate, concurrent to a lateral point, subclose,
broad (≤ 3 mm broad), more or less ventricose,
lamellulae up to three different lengths. Stipe
absent or as a lateral, cylindric, whitish,
glabrous knob (when seen from the hymeno-
phore) but the pileus is laterally or dorsally
attached to the substratum. Context somewhat
translucent, watery, more or less thick (2-5 mm
thick), hygrophanous then becoming opaque,
soft, elastic, unchanging on exposure. Odor and
taste not distinctive.
Basidiospores 6.5-8.5(-9) × 4-5 µm,
x
=
7.2-8 × 4.2-4.8 µm, Q =1.65–1.88, ellipsoid to
more or less narrowly amygdaliform, often rath-

24
Fig. 10. Crepidotus albescens. a. Basidiospores. b. Basidia. c. Cheilocystidia. d. Pileipellis (Mata 870). Bars: a-c = 10
µm, d = 20 µm.

Fungal Diversity
25
Fig. 11. Crepidotus albescens. a. Pileus and hymenophore in tangential section showing the refringent, gelatinized layers
of context and subhymenium. b. Mediostratum and laterostrata (gelatinized) in a lamella in tangential section (Mata
1272). c. Pileipellis. d. Cheilocystidia (Mata 870). Bars: a-c = 50 µm, d = 10 µm.
er depressed adaxially then more or less
narrowly reniform, moderately attenuated
towards the apex but rounded apically, apiculus
inconspicuous, smooth, thick-walled (< 1 µm
wide), yellowish to pale yellowish-brown.
Basidia 20-32 × 6-8 µm, 4-spored, occasionally
tri- or monosporic forms are present, clavate to
narrowly clavate, thin-walled, hyaline, clamped.
Pleurocystidia absent. Cheilocystidia (35-)38-
119 × 3-6(-7) µm, numerous, subcylindric or
slightly broadened downwards, then elongate
and more or less narrowly lageniform (or
occasionally narrowly utriform), prominently
projected above the hymenium level, often
somewhat sinuous towards the base, apex
rounded, occasionally attenuated (2-)3-7 µm
wide, neck rarely with short, lateral outgrowths
or bifurcate, hyaline, thin- or slightly thick-
walled (< 0.5 µm thick), clamped, not or weakly
gelatinized producing a more or less dense,
refringent layer on lamellae edge. Pileipellis a
moderately broad (± 75-125 µm deep) non-
gelatinzed, hyaline layer forming a cutis or a
transition between a loose cutis and a loose
trichoderm, with a variable number of undiffe-
rentiated, repent or often erect terminal
elements, consisting of more or less filamen-
tous, (1-)2-4(-6) µm wide, hyaline, somewhat
loosely interwoven or entangled hyphae, occa-
sionally some segments pale yellowish, simple
or bifurcate, moderately sinuous, often curved,
at times with short, lateral outgrowths, clamped,

26
Fig. 12. a. Crepidotus pseudoantillarum (Bandala 4211). b. Crepidotus herrerae (Bandala 3895). Bars = 20 mm.
thin- or slightly thick-walled (≤ 0.5 µm thick),
smooth or at times some segments obscurely
encrusted (colorless). Pileus trama (in tangential
section) differentiated in two layers, one benea-
th pileipellis, gelatinized, refringent, variable in
depth, composed of more or less filamentous

Fungal Diversity
27
hyphae (1-)2-4(-5) µm wide, hyaline, some
segments with a dense, yellowish content, thin-
walled, smooth or occasionally obscurely punct-
ate, somewhat flexuous, more or less radially
oriented and loosely interwoven; below that
layer is a distinctive, moderately compact to
loose, gelatinized but not refringent stratum
comprising most of the pileus context and
composed of colorless, thin-walled, subcylindric
to subventricose, simple or bifurcate hyphae (2-)
5-19 µm wide, often elongate-bifurcate, some-
what radially oriented. Hymenophoral trama
with a mediostratum, subregular to regular,
composed of cylindric to subventricose, com-
pactly arranged, hyaline, non-gelatinized hyphae
5-19 µm wide; laterostrata refringent, gelatini-
zed, composed of filamentous, colorless to pale
yellowish, thin-walled hyphae (1-)2-3(-5) µm
wide, loosely and more or less divergently
arranged. Clamp connections present in all
tissues.
Habitat: Gregarious, on a decaying wood,
in tropical forest, at 1300-1700 m alt.
Known distribution: Canada, Costa Rica,
U.S.A.
Material examined: COSTA RICA. Puntarenas:
La Amistad, Pacífico, Z.P. Las Tablas, Finca
Confragosa, 19 September 2000, Mata 870; Finca La
Neblina, 8 June 2005, Mata 1272 (INB).
Other material examined: CANADA. Ontario:
Perry Sound District, September 1919, Kelly 158 (MICH,
holotype of Crepidotus phaseoliformis). U.S.A.
Michigan: Cheboygan Co., Reese’s Bog, University of
Michigan Biol. St., 24 July 1963, A.H. Smith 66940;
Ogemaw Co., Ogemaw Reserve, 4 September 1963,
A.H. Smith 67413 (both at MICH as Crepidotus
betulae). New York: on fallen twigs of Betula lenta,
New York Botanical Garden. June 1902, F.S. Earle 241
(NY, holotype of Crepidotus betulae); on birch, New
York Botanical Garden, 4 September 1915, W.A. Murrill
s.n. (NY, holotype of Geopetalum albescens).
Notes: Crepidotus albescens is a modera-
tely small, white fungus that is differentiated
from closely allied species by its distinctive
elongate cheilocystidia, the pileipellis with
cylindric to filamentous, undifferentiated
terminal elements and the relatively narrow and
small basidiospores. Crepidotus phaseolifor-
mis, thought to be a separate species (Hesler
and Smith, 1965), was synonymized with C.
albescens since Redhead (1984) found that
both share the same pattern of taxonomically
critical characters (i.e. tramal and subhymenial
tissues, spores, cystidia and clamped hyphae).
Our results largely agree with Redhead but we
found also that the variation shown by the
characters supporting C. betulae (Fig. 9) over-
laps within the range of variation exhibited by
C. albescens. We interpret that as well as C.
phaseoliformis, specimens of C. betulae also
represent the individual variation of members
of C. albescens hence we propose here C.
betulae as a later synonym. While C. albescens
was described as having glabrous pileus, that of
C. phaseoliformis and C. betulae was recorded
as appressed fibrillose (or the fibrils more or
less erect when young) or villose with felted
hairs, glabrous towards the margin with age,
respectively (Murrill, 1916, 1917; Hesler and
Smith, 1965). Macroscopic description above
is based on the Costa Rican specimens that
showed all the characters of C. albescens.
Microscopically the pileipellis of all examined
collections is very similar. The upper layer of
pileus displays to a greater or lesser degree a
moderately compact or loose arrangement of
the hyphae. Consequently the hyphal arrange-
ment is interwoven with radially orientation
recalling a more or less lattice-like structure.
The pileipellis varies also in thickness and in
number of repent or erect, undifferentiated
terminal elements. Due to gelatinous consisten-
cy of the basidiome, some dried samples are
somewhat tough which often prevents the
complete rehydration of the outermost layer (as
occurs often with samples of the C. mollis
group). This layer then appears as a compact,
entangled layer of radially oriented hyphae.
Since all examined specimens exhibit the same
kind of hyphae and share a similar hyphal
arrangement of the pileipellis, we are not
convinced that the variation shown by the
pileipellis is of taxonomic value to distinguish
more than one taxon. Apart of individual
variation, it depends perhaps on the basidiomes
age, on the variable abundance of superficial
tomentum in individual collections, on the
point between the base and the pileus margin
from which the hand section was taken or even,
the proper dehydration of the sample.
Crepidotus albescens has been collected
in the eastern part of North America [Ontario
(Canada), Michigan, New Hampshire, New
York, and southwards, in Tennessee and
Virginia (USA)], inhabiting Alnus, Betula,
Fagus and other deciduous forests (Murrill,
1916, 1917; Hesler and Smith, 1965). The

28
present record in Costa Rica is interesting and
perhaps indicates that C. albescens has a
potentially wide range of extension, also
reaching the more diverse broad-leaved forests
from the south.
Acknowledgements
We acknowledge the loan of specimens from the
herbaria FH, MICH and NY. We express our thanks to
Dr. T.J. Baroni (State University of New York, College
at Cortland) for reviewing the manuscript and providing
suggestions. Part of this work was supported by
CONACYT (Project 52364-Q to V.M. Bandala).
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