フウノミタケ

Phaeomarasmius laccarioides Har. Takah., Mycoscience 42: 347-353, 2001

傘は非吸水性で湿時条線を欠き、傘と柄の表面は白色の繊維状小鱗片(被膜の名残)に被われます。外観はチャムクエタケの仲間に酷似していますが、傘の表皮は厚壁の球形細胞からなる平行菌糸被 (チャムクエタケ属は糸状菌糸)。ヒダが上生～直生でツバを欠くチャムクエタケモドキっぽい類型はムクエタケ型(naucorioid) と呼ばれることがあります。地上に落下したモミジバフウの実から発生。

肉眼的特徴: 傘は径 7-15 mm, 最初半球形で縁部は内側に巻き, のち饅頭形～ほぼ平開

し, 非吸水性, 湿時半透明の条線を欠く, 表面は白色の繊維状小鱗片 (被膜)に被われ, 地色

は一様に赤褐色. 肉は厚さ 1.5 mm以下, 表面と同色, 特別な味や臭いはない. 柄は 15-30×1.

3-3 mm, ほぼ上下同大または根本に向かってやや拡大し, 中心生, やせ型, 中空, 傘より淡

色, 最初白色の繊維 (被膜)に被われるがのち平滑になり, 類白色の繊維状クモの巣膜を有し,

根本は白色剛毛状菌糸体に被われる. ヒダは直性～やや垂生し, 疎 (柄に到達するヒダは 15

-18), 幅 4 mm以下, 傘と同色 (赤褐色); 縁部は長縁毛状 (fimbriate), 縁取りを欠く.

顕微鏡的特徴: 担子胞子は 5.5-7×4-5μm [Q = length/breadth: 1.37-1.40], 楕円形, 平

坦, 淡褐色, 薄壁, 発芽孔を欠く. 担子器は 28-38×7-8μm, こん棒形, 4 胞子性. 偽担子器

はこん棒形～類こん棒形, 縁シスチジアは 25-32×5.5-7μm, 群生し, 円柱形～類こん棒形,

平坦, 無色, 薄壁. 側シスチジアはない. 子実層托実質はやや平列型; 菌糸は傘実質と共通す

る. 傘の表皮は数珠状に連なる肥大した厚壁細胞からなる平行菌糸被; 菌糸は幅 5-20μm,

円柱形または球形～長楕円形, しばしば分岐し, 褐色の色素粒に厚く被われ, 厚壁, 時に隔壁

にクランプを持つ. 傘実質の菌糸は幅 5-22μm, 並列し, 円柱形, 褐色の色素粒に被覆され,

厚壁, 時に隔壁にクランプを持つ. 柄の表皮は平行菌糸被; 菌糸は幅 2-12μm, 円柱形, しば

しば褐色の色素粒に被覆され, 厚壁, 時に隔壁にクランプを持つ; 柄シスチジアは散生し, 縁シ

スチジアと同形. 柄の実質は縦に沿って配列した円柱形の菌糸 (幅 7-20μm) からなり, 無分

岐, 淡褐色, やや厚壁 (0.5μm), 時に隔壁にクランプを有する.

供試標本: KPM-NC0006568 (基準標本), Ikuta-ryokuchi, Kawasaki- shi, Kanagawa-ken,

14 May 2000, coll. E. Sano; KPM-NC0006722, the same place, 18 Jun. 2000, coll. H.

Takahashi.

コメント: 小型で非吸水性、赤褐色の子実体は繊維状の被膜に被われ, 傘の表皮は厚壁の

球形細胞からなる. 神奈川県川崎市生田緑地の地上に落下したモミジバフウの実から発生.

標本は神奈川県立生命の星・地球博物館の標本庫(KPM)に登録, 収蔵されている.

Phaeomarasmius laccarioides Har. Takah., Mycoscience 42: 347-353, 2001　

Pileus 7-15 mm in diam, at first hemispherical with involute margin, then plano-convex to

plane, non hygrophanous, surface whitish squamulose-fibrillose all over, background evenly

colored brownish red (8C7-8) to reddish brown (8D7-8 to 9D7-8). Flesh up to 1.5 mm,

concolorous; odor and taste not distinctive. Stipe 15-30×1.3-3 mm, subequal or somewhat

thickened toward the base, central, slender, terete, hollow, paler concolorous with the pileus,

whitish fibrillose when young, glabrescent in age, with whitish fibrillose cortina; base covered

with white strigose mycelium. Lamellae adnate to subdecurrent, distant (15-18 reach the

stipe), up to 4 mm broad, concolorous with the pileus; edges fimbriate, concolorous.

Basidiospores 5.5-7×4-5 μm [Q = length/breadth: 1.37-1.40], ellipsoid, smooth, pale

brown, thick-walled, without a germ pore. Basidia 28-38×7-8 μm, clavate, four-spored.

Basidioles clavate. Cheilocystidia 25-32×5.5-7μm, abundant, cylindric to subclavate,

smooth, colorless, thin-walled. Pleurocystidia absent. Hymenophoral trama regular; element

hyphae similar to those of the pileitrama. Pileipellis a cutis consisting of chains of highly

inflated elements; constituent cells 5-20μm wide, cylindric or globose to oblong, often

branched, heavily incrusted with granules of brown pigment, with brownish, thickened walls,

occasionally with clamped septa. Hyphae of pileitrama 5-22 μm wide, parallel, cylindric, with

incrusting, brown pigment, with brownish, thickened walls, occasionally with clamped septa.

Stipitipellis a cutis of parallel, repent hyphae 2-12 μm wide, cylindric, often incrusted with

granules of brown pigment, with brownish, thickened walls, occasionally with clamped septa;

caulocystidia, scattered, similar to the cheilocystidia. Stipe trama composed of longitudinally

running, cylindric hyphae 7-20 μm wide, unbranched, pale brownish, slightly thick-walled,

occasionally with clamped septa.

Known distribution: Japan (Kanagawa).

Habitat: Solitary to scattered, on fallen fruit of Liquidambar styraciflua, from May to

June, not common.

Specimens examined: KPM-NC0006568 (holotype), Ikuta-ryokuchi, Kawasaki- shi,

Kanagawa-ken, 14 May 2000, coll. E. Sano; KPM-NC0006722, the same place, 18 Jun. 2000,

coll. H.Takahashi.

Japanese name: Fuunomitake.

Notes: This species is characterized by its small basidiomata with a squamulose-fibrillose,

non hygrophanous, reddish brown pileus, the pale brown, smooth, thick-walled basidiospores

without a germ pore, the cylindric to subclavate cheilocystidia, the pileipellis consisting of

chains of highly inflated, thick-walled elements with heavily incrusting, brown pigment, and

the habitat on fallen fruit of Liquidambar styraciflua.

Its centrally stipitate basidiomata, the less than 8 μm long basidiospores, and the

presence of sphaerocysts in the pileipellis suggest that it is a member of the genus

Phaeomarasmius Scherff. subgenus Carpophilus Singer (Singer, 1986), where it appears to

be closely related to European Phaeomarasmius granulosus (J.E.Lange) Singer (Lange, 1939;

Watling, 1967; Vellinga, 1986) which differs in having a dark brown pileus, fusiform-

amygdaliform, longer basidiospores (8-9.5×4-5.5 μm: Vellinga, 1986), narrowly lageniform

cheilocystidia, and a terrestrial habitat. Phaeomarasmius melanesius Corner & Horak from

Solomon Islands (Horak, 1980), which belongs to the subgenus Phaeomarasmius (Singer,

1986), is also similar to P. laccarioides. The former species, however, differs in having a

ferruginous pileus, a pileipellis made up of elongated, thin-walled elements, and habitat on

rotting branches.