サカゲチャヒラタケ

Crepidotus longicomatus Har. Takah., Mycoscience (2003) 44: 103-107

傘は逆立った長い毛に被われ、ケブカちゃんをヒラタケ型にしたような微小なきのこ(傘径 1-3.5 mm)です。チャヒラタケ属に近縁種はなく、系統的な類縁関係が全くわからない高尾山の謎の妖菌です。

子実体は真性の柄を欠き、厚壁な菌糸からなる長軟毛に被われた傘(径 1-3.5 mm)を形成し、胞子は蜜色、広楕円形で微細な疣状突起を持つ特徴があります。

肉眼的特徴: 子実体は微小 (径 1-3.5 mm), 軟質, 無柄または退化した短い柄を持ち, 側

生, 時に背着生, 腎臓形～半円形. 傘の表面は全体に白色～淡黄色の直立した長毛が密生す

る; 縁部は最初内側に巻く. 肉は厚さ 0.2 mm 以下, 白色～淡黄色, 特別な臭いはない. ヒダは

疎 (基部に到達するヒダは 6-10), 幅 0.5 mm 以下, 淡黄色, 縁部は同色.

顕微鏡的特徴: 胞子は 6-8×4.5-5μm, 広楕円形, 蜜色, 厚壁, 微細な疣状突起を持つ. 担

子器は 20-35×7-8.5μm, こん棒形, 2胞子性. 縁シスチジア及び側シスチジアを欠く. 傘の表

皮を形成する長毛は垂直に配列し, 長さ 1000μmに達し, 幅 3.5-8 (-10) μm, 円柱形, 無色ま

たは淡い蜜色, 厚壁 (1.5μm), 時に隔壁にクランプを持つ.

供試標本: KPM- NC0008716 (基準標本), Mt.Takao, Hachiouji-shi, Tokyo, Japan, June 20,

2000, coll. H.Takahashi; the same place, June 23, 2001, coll. H.Takahashi.

Japanese name: Sakage-chahira-take.

コメント: マルミノチャヒラタケ節 (Section Echinospori) に属し, ヒラタケ型の微小な (３mm前

後) 子実体を形成し, 傘の表面に淡黄色の直立した長毛が密生する. 微小な子実体及び直立

した厚壁な長毛を有する特徴において, 本属では特異な種類である. 東京都高尾山の林内落

枝上に発生.

Crepidotus longicomatus Har. Takah., Mycoscience (2003) 44:103-107　

Basidiomata very small (1-3.5 mm in diameter), soft, sessile or with a short stipe, lateral

or sometimes dorsal, reniform to semiorbicular. Pileus densely covered overall with white to

pale yellow, erect, long hairs; margin at first incurved then straight. Flesh up to 0.2 mm thick,

white to pale yellow; odor indistinctive. Lamellae distant (6-10 reach the base), with 1-3

series of lamellulae, up to 0.5 mm broad, pale yellow; edges concolorous.

Basidiospores 6-8×4.5-5μm, [Q = length/breadth: 1.3-1.6, n = 20 spores per two

specimens], broadly ellipsoid, melleous in water, thick-walled, surface distinctly echinulate,

with concolorous spines 0.5-1 μm long. Basidia 20-35×7-8.5μm, clavate, two-spored.

Cheilocystidia and pleurocystidia none. Hymenophoral trama subregular to irregular; hyphae

similar to those of the pileitrama. Pileipellis composed of vertically arranged, parallel, long

hairs up to 1000 μm long, 3.5-8 (-10) μm wide, cylindrical, colorless or with pale melleous,

intracellular, granular pigments, with thickened walls up to 1.5 μm, occasionally with

clamped septa. Hyphae of pileitrama 4-10 μm wide, parallel to each other, cylindrical or

sometimes irregularly inflated, colorless or with pale melleous intercellular pigments, thin or

slightly thick-walled.

Known distribution: Japan (Tokyo).

Habitat: Solitary to scattered, on fallen dead twigs in lowland oak forests, from June to

July.

Specimens examined: KPM- NC0008716 (holotype), Mt.Takao, Hachiouji-shi, Tokyo,

Japan, June 20, 2000, coll. H.Takahashi; the same place, June 23, 2001, coll. H.Takahashi.

Japanese name: Sakage-chahira-take.

Notes: This species is characterized by its very small (up to 3.5 mm in diameter) reniform

basidiomata densely covered overall with white to pale yellow, erect, thick-walled, long hairs,

the melleous, echinulate basidiospores, the lack of hymenial cystidia, and its basidiome

formation on a fallen dead branch. These characteristics suggest that this species belongs

to the section Echnospori Pilat of the genus Crepidotus as defined by Singer (1986).

However, this species is distinguished from other known species of the genus by the very

small basidiomata with the pileus densely covered overall with erect, thick-walled, long hairs.