モウセンアシベニイグチ (2014年1月19日更新)
Boletus panniformis Taneyama & Har. Takah., Mycoscience Volume 54:458-468, 2013
(Available online 25 April 2013: http://www.sciencedirect.com/science/article/pii/
MycoBank no.: MB564206
Etymology: from Latin, panniformis = felted.
Immature basidioma (Holotype). Bar 20 mm. 種山裕一氏撮影
Close up of the pileus surface (TNS-F-44629). 2 mm. 種山裕一氏撮影
Micromorphological features of Boletus panniformis (Holotype): 3 Elements of the pileipellis.
4 Cheilocystidia. 5 Pleurocystidia. 6 Basidia. 7 Basidiospores. 8 Caulocystidia from the upper
portion of stipe. 9 Caulobasidia. 10 Caulocystidia from the lower portion of stipe. Bars 3-6
and 8-10 20 μm; 7 10 μm. 原図: 種山裕一氏
生態: ウラジロモミ (Abies homolepis), オオシラビソ（A. mariesii）, トドマツ (A. sachalinensis)を
主体とする亜高山帯の針葉樹林内地上に孤生～散生, 7月～9月.
分布: 日本 (長野, 山梨, 北海道).
主な形態的特徴:
１）傘の表面は褐色～帯褐橙色を帯び, 通常小鱗片状を成す.
2) 柄は全体に赤色を帯び, 表面と同色の繊細な網目模様を表す.
3) 肉は空気に触れると徐々に青変し, 苦みを有する.
4) 柄シスチジアは類円柱形～紡錘形で, 薄壁.
所属位置並びに近縁種
赤色を帯び且つ繊細な網目模様を表す柄並びに苦みを有する肉の性質は, 欧州を中心に
分布するアシベニイグチ B. calopus と共通するが, 欧州産アシベニイグチは傘の表面が密綿
毛状～ほぼ滑らかで, 傘実質の菌糸はアミロイドに反応し, 柄の表皮組織にフラスコ形の厚壁
シスチジアを持つと言われている. 北米産 Boletus rubripes Thiers (Thiers 1965, 1975;
Bessette et al. 2000) も近縁種と考えられるが, 小鱗片を形成しない傘表面および網目模様を
欠く柄の特徴においてモウセンアシベニイグチと異なる.
Macromorphological features:
Pileus (Figs. 1, 2) 60-140 (-170) mm in diam, at first hemispherical, expanding to broadly
convex, with slightly appendiculate, straight margin; surface dry or sometimes subviscid
when wet, felty-tomentose to velvety, smooth or more often becoming minutely tessellated-
scaly almost overall when old, light brown (6D4-5) to brown (6E5) at first, then blond (4C4)
to brownish orange (5C5-6C5), tinted dark brown (7F5-6F5) to reddish brown (8E4-5) in the
scales, unchanging when bruised. Flesh up to 25 (-30) mm thick at the center of the pileus,
becoming very thin toward the margin, pale yellow (4E3), at times stained greyish red (10C5)
to brownish red (10C6) at the base of stipe and right beneath the pileus and the stipe
surfaces, gradually changing to blue when cut, yellow (3A4) or orange (5A6) in KOH, negative
in NH4OH, negative or bluish in guaiac, brownish in phenol, inamyloid; taste bitter, odor
indistinct. Stipe (Fig. 1) 65-130 × 15-35 mm, subcylindrical or somewhat thickened toward
the base, central, terete, solid; surface dry, red (11A7 to 11B7-8) downward, greyish yellow
(4B6) at the apex, densely covered overall with reddish brown (8E5-9D5) to greyish red
(10D4) pruina, finely but conspicuously reticulated over the upper half by a thin-veined,
concolorous reticulum with meshes subequal (above) to longitudinally elongated (below),
gradually changing to blue where handled; basal mycelium yellowish white (1A2) to pale
yellow (1A3). Tubes 7-15 (-19) mm deep, depressed around the stipe, light yellow (4A4-5) at
first, becoming greyish yellow (2B5-6) with age, instantly changing to blue when exposed;
pores 2-3 per mm, subcircular, concolorous with the tubes, sometimes with reddish stains,
instantly changing to blue when bruised. Spore print olive (2E4).
Micromorphological features:
Basidiospores (Fig. 7) (11.3-) 13.6-15.2 (-16.4) × (4.6-) 5.4-6.0 (-6.5) μm (n = 266,
mean length = 14.37 ± 0.78 μm, mean width = 5.69 ± 0.28 μm, Q = (2.0-) 2.4-2.7 (-3.3),
mean Q = 2.53 ± 0.17), inequilateral with a shallow suprahilar depression in profile, subfusoid
in face view, with a rounded apex, smooth, greenish grey (1B2) in water, greyish yellow (4B5)
in KOH, inamyloid or infrequently weakly dextrinoid, with slightly thickened walls (up to 0.5 μ
m). Basidia (Fig. 6) (24.2-) 26.6-33.2 (-38.9) × (10.8-) 11.6-13.0 (-14.4) μm, clavate, 4-
spored; sterigmata (3.0-) 3.5-4.7 (-5.3) × (1.5-) 1.8-2.4 (-3.0) μm. Basidioles clavate.
Cheilocystidia (Fig. 4) abundant, forming a compact sterile edge, (18.6-) 22.8-32.2 (-37.4) ×
(4.4-) 5.7-7.9 (-10.2 ) μm (n = 94, mean length = 27.49 ± 4.67 μm, mean width = 6.78 ± 1.
12 μm), narrowly fusoid-ventricose to ventricose-rostrate with an obtuse apex, smooth,
hyaline in water and KOH, inamyloid, thin-walled. Pleurocystidia (Fig. 5) scattered, (35.3-) 38.
8-56.1 (-77.6) × (6.3-) 7.3-10.2 (-14.5) μm (n = 49, mean length = 47.43 ± 8.63 μm,
mean width = 8.77 ± 1.47 μm), similar in shape to cheilocystidia. Hymenophoral trama
bilateral-divergent of the Boletus-subtype; elements 6.0-7.9 ?m wide in lateral strata, 3.0-4.
4 ?m wide in a mediostratum, cylindrical, smooth, colorless in water and KOH, thin-walled.
Pileipellis (Fig. 3) made up of loosely entangled hyphal ends; constituent hyphae of the
scales 5.9-9.4 μm wide, cylindrical, spirally encrusted with brownish (5C4-5) granular
pigment (in water) that are not dissolved in KOH, inamyloid, reddish (6C8) in KOH, thin-
walled. Pileitrama of cylindrical, loosely interwoven hyphae 5.3-9.6 μm wide, smooth,
colorless in water and KOH, inamyloid or weakly dextrinoid, thin-walled. Stipitipellis consisting
of tufts of caulocystidia and infrequent caulobasidia; caulocystidia (Fig. 8) at the upper
portion (24.4-) 30.0-54.2 (-100.4) × (4.1-) 6.4-8.9 (-12.0) μm (n = 134, mean length = 42.
11 ± 12.08 μm, mean width = 7.69 ± 1.25 μm), subclavate or narrowly fusoid-ventricose
to ventricose-rostrate, at times subcylindrical, reddish (9C7) in water, yellowish (3A3) in
KOH, inamyloid; caulocystidia (Fig. 10) at the lower portion (41.1-) 50.1-99.6 (-148.6) × (4.7
-) 6.0-7.8 (-8.9) μm (n = 38, mean length = 74.87 ± 24.77 μm, mean width = 6.90 ± 0.93
μm), subcylindrical, occasionally 1-2 septate, brownish (5C4) in KOH; caulobasidia (Fig. 9)
(26.7-) 31.4-40.2 (-45.2) × (10.1-) 10.6-12.0 (-12.9) μm, 2- to 4-spored, yellowish (3A3) in
KOH, inamyloid. Stipe trama composed of longitudinally running, cylindrical cells (4.7-) 6.3-10.
8 (-15.0) μm wide, unbranched, smooth, colorless in water, hyaline in KOH, dextrinoid, thin-
walled. Clamp connections absent.
Habitat: Solitary to scattered, on ground in highland (subalpine) forests dominated by
Abies homolepis Sieb. & Zucc. and A. mariesii Mast. and A. sachalinensis (F.Schmidt) Mast.,
July to September.
Known distribution: Japan (Nagano, Yamanashi, Hokkaido).
Specimens examined: TNS-F-44623 (Holotype; Isotype KPM-NS0017979), Takayama-
mura, Kamitakai-gun, NaganoPref., on ground in highland forests dominated by A. homolepis,
1600 m alt., 23 July 2011, coll. Taneyama, Y; TNS-F-44624, the same place, 23 July 2011,
coll. Taneyama, Y; TNS-F-44621, the same place, 6 July 2010, coll. Taneyama, M; TNS-F-
44618, Houkousha, Togakushi, Nagano-shi, Nagano Pref., on ground in highland forests
dominated by A. homolepis, 1080 m alt., 3 July 2009, coll. Taneyama, M; TNS-F-44620, the
same place, 8 July 2009, coll. Taneyama, M; TNS-F-44622, the same place, 6 July 2011, coll.
Taneyama, M; TNS-F-44628, the same place, 17 July 2008, coll. Taneyama, Y; TNS-F-
44619, Karuizawa-cho, Kitasaku-gun, Nagano Pref., on ground in highland forests dominated
by A. homolepis, 1000 m alt., 7 July 2009, coll. Uchibori, A; TNS-F-44629, Okusha, Togakushi,
Nagano-shi, Nagano Pref., on ground in highland forests dominated by A. homolepis, 1220 m
alt., 11 July 2009, coll. Taneyama, M; TNS-F-44626, Shikotsu-Rake, Tomakomai-shi, Hokkai-
do, on ground in highland forests dominated by A. sachalinensis, 240 m alt., 12 sept. 2011,
coll. Taneyama, Y; TNS-F-44627, the same place, 12 sept. 2011, coll. Saito, K; TNS-F-
44625, Mt. Fuji, Yamanashi Pref., on ground in highland forests dominated by A. mariesii,
1780 m alt., 28. Aug. 2011, coll. Taneyama, Y.
Japanese name: Mousen-ashibeni-iguchi.
Comments: Boletus panniformis has the characteristics of the brown pileus typically
covered overall with small, matted scales, the cyanescent, bitter flesh, the finely reticulate,
red stipe, the subcylindrical to fusoid-ventricose caulocystidia, and the habitat in subalpine,
coniferous forests. Especially given the natures of its finely reticulate, red stipe and its
bitter flesh, B. panniformis can be referable to the section Calopodes Fr. sensu str. Sing.
(Singer 1986).
Within the section, Boletus calopus Pers. originally described from Europe (Persoon 1801;
Singer 1967; Leclair and Essette 1969; Alessio 1985; Munos 2005) may possibly be related
to B. panniformis in appearance. However, it can be differentiated from the present species
by a tomentose to nearly smooth pileus without scabrosities, amyloid elements in the pileus
trama, and fusiform to lageniform caulocystidia with somewhat thickened walls. Boletus
rubripes Thiers from North America (Thiers 1965, 1975; Bessette et al. 2000) seems to be
also closely related to B. panniformis, though it has its own distinct characteristics in
forming a pale colored, tomentose to appressed-fibrillose pileus and a non-reticulate,
smooth stipe.
References
Alessio CL, 1985. Boletus Dill. ex L. (sensu lato). Fungi Europaei, vol 2. Biella Giovanna,
Saronno.
Bessette AE, Roody WC, Bessette AR, 2000. North American boletes. A color guide to the
fleshy pored mushrooms. Syracuse University
Leclair A, Essette H, 1969. Les Bolets. Paul Lechevalier, Paris.
Munos JA, 2005. Boletus s.l. (excl. Xerocomus). Fungi Europaei, vol 2. Biella Giovanna,
Saronno.
Persoon CH, 1801. Synopsis methodica fungorum 1-706. Gottingen.Press, New York.
Singer R, 1967. Die Pilze Mitteleuropas, vol 6. Julius Klinkhardt Verlag, Bad Heilbrunn.
Singer R, 1986. The Agaricales in modern taxonomy, 4th edn. Koeltz, Koenigstein.
Thiers HD, 1965. California boletes: 1. Mycologia 57: 524-534.
Thiers HD, 1975. California mushrooms, a field guide to the boletes. Hafner Press, New York.