Micromphale sect. Perforantia (Agaricales, Basidiomycetes); Expansion and phylogenetic placement
Author
Petersen, Ronald H.
Ecology & Evolutionary Biology, University of Tennessee, Knoxville, TN 37996 - 1100 USA
repete@utk.edu
Author
Hughes, Karen W.
Ecology & Evolutionary Biology, University of Tennessee, Knoxville, TN 37996 - 1100 USA
text
MycoKeys
2016
2016-12-15
18
1
122
http://dx.doi.org/10.3897/mycokeys.18.10007
journal article
http://dx.doi.org/10.3897/mycokeys.18.10007
1314-4049-18-1
742AFFD8FF9DFFE0FFE1351B1C21FF99
575611
10.
Gymnopus sequoiae (Desjardin) R.H. Petersen
comb. nov.
Basionym.
Micromphale sequoiae
Desjardin. 1985
. Mycologia 77: 894-895.
Holotype.
United States
,
California
, Mendocino Co., Jackson State Forest, junction of state roads 408 & 409, 13.XI.1982, coll & det D.E. Desjardin, DED 1740 (SFSU-F-000711).
Diagnosis
(fide
Desjardin 1985
). 1) fruiting on needle debris of
Sequoia sempervirens
; 2) light brown to flesh-colored, rugulose pileus; 3) lamellae concolorous with pileus; 4) odor mild; 5) grayish-orange to brown pubescent stipe; 6) pileipellis of filamentous hyphae in a slime matrix (no
Rameales
-structure); 7) poorly developed rhizomorphs.
The following description is a rearrangement of the protologue plus observations on dried material.
Basidiomata
(Figs
71
,
72A
) pliant, marcescent, reviving.
Pileus
6-12 mm broad, when young convex to campanulate, often with a short, acute umbo, in age becoming broadly convex to plano-convex with or without a central papilla, occasionally plane with a shallow central depression; margin when young decurved or slightly incurved, even, entire, in age becoming straight, wavy, crenate, rugulose-striate to rugulose-sulcate
1/4
of the distance to center; surface dry to moist, dull glabrous, hygrophanous, at first light brown 7D4-5 overall, rarely with disc reddish brown 8E5-7, in age disc remaining light brown or fading to brownish orange 6C3-4; margin in age fading to brownish orange, greyish orange 6B2-3 or orange white 5A2, in age rarely colored buff overall with a slightly darker disc; pileus trama light brown to brownish orange, soft, up to 1 mm thick.
Lamellae
adnate, free in age or rarely attached to a pseudocol
lar
, close to subdistant, narrow to medium broad (up to 1 mm), rarely anastomosing or intervenose, total lamellae = 25-27, through lamellae = 14-16; at first pale greyish orange 6B2, fading in age to pale orange white 5-6A2, typically concolorous with the pileus margin at maturity; edge even, entire, concolorous; lamellulae in 1-2 series.
Stipe
20-43
x
0.7-1.5 mm broad, terete or rarely apically compressed and cleft, equal or tapered downward, hollow, cartilaginous, insititious; context concolorous with stipe surface; apex pruinose, off-white, downward pubescent and often with furfuraceous base, when young, apical portion pale greyish orange 6B2, central portion light brown 7D4-6, base dark brown 7F5-7 to rusty brown, in age apex becoming pale brownish orange 7C3, central portion becoming brown 7E4-5, base becoming dark brown 7-8F4-8 or occasionally dark brown overall in age.
Rhizomorphs
(Fig.
69A
) short, slender, black, poorly developed, scattered; sterile stipes rare.
Taste
strongly alliaceous after 1-2 minutes;
odor
mild or rarely slightly fetid when old and wet.
Figure 71.
Gymnopus sequoiae
. Basidiomata in natural habitat.
A
Courtesy Michael Wood
B
Ryan Snow, Mushroom Observer. Standard bars = 20 mm.
Figure 72.
Gymnopus sequoiae
.
A
Basidiomata and rhizomorphs
B
Basidiospores. Standard bars:
A
= 10 mm;
B
= 5
µm
. TFB 14620 (TENN-F-69325).
Habitat and phenology.
Scattered to gregarious on branchlets and leaves of
Sequoia sempervirens
; presumably throughout the range of
S. sempervirens
(at least northern California); October-February.
Pileipellis
of inner limb up to 60
µm
thick, involved in a slime matrix; slime material heterogeneous with copious crystal suspension, transparent, not totally soluble in KOH, hyaline; hyphae (Fig.
73A
) 3.6-11
µm
diam, repent, unoriented, interwoven, smooth, thick-walled (wall -1.5
µm
thick), conspicuously clamped (Fig.
73B
) but with frequent secondary septa (Fig.
73C
).
Pileus trama
loosely interwoven; hyphae smooth, non-gelatinized, 4.2-7.2
µm
broad, with hyaline to pale yellowish, inamyloid
walls
up to 1.5
µm
thick.
Lamellar trama
interwoven, of two hyphal types: 1) filamentous hyphae 3.5-7
µm
diam, firm-walled, clamped, not incrusted or gelatinizing; and 2) free-form hyphae, inflated to 13
µm
diam, often articulating with neighboring hyphal segments, firm- to thick-walled (wall -0.7
µm
thick, hyaline); contents with scattered inclusions (PhC).
Pleurocystidia
(Fig.
74A-D
) 21-31
x
7-8
µm
, fusiform, clamped; contents homogeneous, dense (PhC). Basidioles broadly clavate, often becoming ampulliform, clamped; contents multigranular;
basidia
(Fig.
74E-H
) (21-
)
25-30
x
(6-)9-11
µm
, clavate, hyaline, (2-) 4-sterigmate; contents multigranular; sterigmata up to 4.8
µm
long.
Basidiospores
(Fig.
72B
) (6-)6.5-7.5(-8)
x
3-4
µm
(Q = 1.63-2.00; Qm = 1.81; Lm = 6.50
µm
) ellipsoid to lacrymoid, hyaline, smooth, inamyloid, white in deposit. Lamellar edge basically fertile;
cheilocystidia
(Fig.
75
) common but scattered, 27-33
x
4.8-6.6
µm
, clavate or ventricose-rostrate, occasionally submammilate, hyaline and thin-walled, projecting up to 11
µm
beyond basidia.
Stipe medullary hyphae
(Fig.
76A
) free (walls not gelatinized), 3-7.5(-11.5)
µm
diam, thick-walled (wall -1.0
µm
thick, hyaline), conspicuously clamped.
Stipe cortical hyphae
(Fig.
76C
) 4-8.5
µm
diam, thick-walled (wall -1.0
µm
thick), strongly incrusted in thick scabs and annuli, pigmented (yellow-brown, PhC), easily shattering in squash mounts.
Caulocystidia at stipe apex
(Fig.
76B, D, E
) 10-140
x
9-13
µm
, arising from incrusted surface hyphae with somewhat constricted attachment, subventricose and usually tapering slightly distally, thick-walled (wall -2.5
µm
thick, hyaline), often strangulate, often secondarily septate and/or clamped.
Caulocystidia from stipe base
, (Fig.
77B-F
) 25-170
x
9-13
µm
, versiform, irregular in outline with obtuse apices; walls brown, evenly pigmented, -1.2
µm
thick.
Figure 73.
Gymnopus sequoiae
. Pileipellis structures.
A
Hyphae with subgelatinized walls in slime matrix
B
Clamp connection
C
Secondary septa. Standard bars = 10
µm
. TFB 14620 (TENN-F-69325).
Figure 74.
Gymnopus sequoiae
. Hymenial structures.
A-D
Pleurocystidia
E-H
Basidia. Standard bars = 10
µm
. TFB 14620 (TENN-F-69325).
Figure 75.
Gymnopus sequoiae
. Cheilocystidia.
A, B
Clusters of cheilocystidia
C-F
Individual cheilocystidia. Standard bars = 10
µm
. TFB 14620 (TENN-F-69325).
Figure 76.
Gymnopus sequoiae
. Stipe apex structures.
A
Stipe medullary hyphae
C
Strongly incrusted cortical hyphae
C
Young caulocystidium with shagreened surface
B, E
Individual caulocystidia. Standard bars = 10
µm
. TFB 14620 (TENN-F-69325).
Figure 77.
Gymnopus sequoiae
. Lower stipe structures.
A
Stipe surface free-form cells with one caulocystidium
B-F
Individual caulocystidia showing broad-based origin and secondary septa. Standard bars = 10
µm
. TFB 14620 (TENN-F-69325).
Commentary
.
Care was taken to demonstrate all stages of basidiole maturation to demonstrate the difference between young basidioles and cheilocystidial structures. Basidioles are abundant over all of the lamellar surface and are subspherical at the ear
liest
stage, soon becoming broadly clavate and developing a subcapitulate upper portion. Basidia remain broadly clavate throughout spore development. Contents of such structures are consistently multigranular. Although cheilocystidia are similar in dimensions and appearance, contents are homogeneous (PhC), and such structures are found only at the lamellar edge. Conversely, pleurocystidial structures are fusiform from their earliest state, merely elongating to mature size and shape. Contents are homogeneous except for a vacuolated area in midsection (perhaps nucleus; PhC).
Caulocystidia arise as side branches of stipe surface, incrusted hyphae. Early stages of caulocystidial development often bear a shagreened surface but soon becoming smooth. A unique character is the frequent internal secondary septation, as well as occurrence of a clamp connection near caulocystidial origin.
Specimens examined.
California
,
Humboldt Co.
,
Redwood National Park
,
Davidson Rd.
,
N41°12'51"
,
W124°00'12"
,
24.X.1992
, coll & det
DE Desjardin
, DED 5546 (SFSU-F-025665);
Redwood National Park
,
Davidson Rd.
,
N41°12'51"
,
W124°00'12"
,
24.X.1992
, coll & det
DE Desjardin
, DED 5546 (SFSU-F-025665);
Mendocino Co.
, vic.
Fort Bragg
,
Simpson Lane
,
28.IX.1986
, coll & det
H.D.Thiers
,
HDT 50541
(SFSU-F-025669);
Jackson State Forest
,
Hwy
408 at junction with road to
Mendocino Woodlands
,
21.XI.2015
, coll & det
DE Desjardin
, DED 8802/
TFB 14620
(TENN-F-69325);
Jackson State Forest
, along
Hwy
409 car
1 mi
from junction of
Hwy
408,
18.XI.1995
, coll & det
DE Desjardin
, DED 6316 (SFSU-F-025662); same loca
tion
,
13. Nov. 1982
, DED 1740 (
holotype
); same location,
Hwy
409,
13.XII.1990
, coll & det
D.E. Desjardin
, DED 5023 (SFSU-F-025663); same location, "Aleuria Glen,"
29.X.1990
, coll
H.D. Thiers
, det
D.E. Desjardin
, DED 5012 (SFSU-F-025668)
.