イズミノアシナガタケ

Mycena fonticola Har. Takah., Mycoscience (2007) 48: 342-357.　

アクニオイタケ節 (section Fragilipedes) の仲間で、スミレロクロタケ (スミレアシナガタケ)に近縁と思われます。

肉眼的特徴: 傘は径 10-25 mm, 釣り鐘形で平開せず, 多少とも浅い放射状の溝線を表 し,

湿時半透明の条線を表し, やや吸水性, 乾性, 平滑, 全体に紫褐色.　肉は傘の中央部におい

て厚さ 1mm 以下, 白色, 特別な味や臭いはない. 柄は 70-100×1-2.5 mm, 円柱形, 根本が僅

かに拡大し, 中心生, やせ型, 中空, 乾性, 最初白色粉状, のち平滑になり, 全体に傘と同色, 根

本は白色の剛毛に被われる. ヒダは上生し, 柄に到達するヒダは 23-27, 幅 2.5 mm以下, 白色

または淡灰色, 縁取りを欠く.

顕微鏡的特徴: 担子胞子は 11.5-14×6-8 μm, 楕円形, 表面は平坦, 無色, 濃アミロイド, 薄

壁. 担子器は 17-28×6-8 μm, こん棒形, 4胞子性. 縁シスチジアは 32-39×5-12 μm, 群生

し, 紡錘形, 無色, 平坦, 薄壁. 側シスチジアを欠く. 子実層托実質の菌糸は偽アミロイド. 傘の

上表皮層の菌糸は匍匐性で, 幅 2-5μm, 平行に配列し, 円柱形, 疣状～短指状突起に被わ

れ, 無色または細胞内に褐色の色素が存在し, 薄壁, 非アミロイド. 上表皮下層の菌糸は無色

または細胞内に褐色の色素が存在し, 実質の大部分は偽柔組織状 [pseudoparenchymatous:

著しく肥大し, 複数の隔壁を持った短形の菌糸細胞] で, 菌糸は平列 し，偽アミロイド. 柄表皮

の菌糸は疣状～短指状突起に被われ, 無色または細胞内に褐色の色素が存在する. 菌糸は

クランプを欠く.

供試標本: KPM-NC0007439 (holotype), Izumino-mori, Yamato-shi, Kanagawa pref., 21

Nov. 2000, coll. H.Takahashi; the same place, 25 Nov. 1999 coll. H. Takahashi; the same

place, 27 Nov. 1999, coll. H.Takahashi; the same place, 16 Nov.2000, coll. H. Takahashi.

コメント: 傘と柄は平滑, 紫褐色で, 胞子はやや大型で濃アミロイド, 縁シスチジアは平坦, 紡

錘形で, 側シスチジアを欠き, 傘と柄の表皮組織は多分枝菌糸からなり, 菌糸はクランプを欠

く. 晩秋の頃 (11月), 神奈川県大和市泉の森のシラカシ, コナラを中心とする広葉樹林内の落

ち葉または落枝上に発生. 標本は神奈川県立生命の星・地球博物館 (KPM) の標本庫に登

録, 収蔵されている.

本種は Maasの分類概念 (Maas 1980, 1988a) によるアクニオイタケ節 (section

Fragilipedes) に属し, 本州中部産スミレアシナガタケ Mycena mustea Har.Takah. は本種に最

も似るが, 淡灰紫色の傘, 頂部に疣状突起を具えたこん棒形の縁シスチジア, そして柄の表皮

組織において平滑な菌糸を持つ点で異なる.

Mycena fonticola Har. Takah., Mycoscience (2007) 48: 342-357.

　 Etymology: From Latin, fonticola = dweller in fountain.

Pileus 10-25 mm in diam, conico-convex to campanulate, more or less shallowly sulcate-

striate almost to the disc, subhygrophanous, dry, glabrous, evenly colored violet brown (10F5

-7 to 11F5-7) when young, then somewhat paler from the margin. Flesh up to 1 mm, white;

odor and taste not distinctive.　Stipe 70-100×1-2.5 mm, cylindrical, slightly enlarged at the

base, central, slender, terete, hollow, dry, greyish brown (10F3) to violet brown (10F4) at the

apex, violet brown (10F4-6) downward, at first entirely white pruinose, glabrescent in age;

base white strigose.　Lamellae adnexed, 23-27 reach the stipe, up to 2.5 mm broad, thin,

whitish or with a grayish hue; edges concolorous.

　Basidiospores (n = 61 spores of 5 basidiocarps) 11.5-14×6-8 μm, Q (length/breadth) =

1.7-1.9, ellipsoid, smooth, colorless, distinctly amyloid, thin-walled.　Basidia 17-28×6-8 μm,

clavate, four-spored. Basidioles clavate.　Cheilocystidia 32-39×5-12 μm, abundant,

forming a sterile lamella edge, fusiform to subclavate, often apically broadly rounded,

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

hyphae 7-15 μm wide, cylindrical, walls thin, smooth, colorless, dextrinoid.　Pileipellis a cutis

of parallel, repent hyphae 2-5 μm wide, cylindrical, densely covered with warty or finger-

like diverticulae, walls thin, colorless or with cytoplasmic brownish pigment, inamyloid;

underlying hyphae parallel, colorless or with cytoplasmic brownish pigment, dextrinoid, with

short and inflated cells up to 30 μm wide.　Stipitipellis a cutis of parallel, repent hyphae 3-5

μm wide, cylindrical, covered with scattered, warty or finger-like diverticulae, colorless or

with cytoplasmic brownish pigment, inamyloid, thin-walled.　Stipe trama composed of

longitudinally running, cylindrical hyphae 5-17 μm wide, smooth, colorless, dextrinoid.　

Clamp connections absent in all tissues.

Known distribution: Japan (Kanagawa).

　 Habitat: Solitary or scattered, on dead leaves and twigs in lowland forests dominated

by Quercus myrsinaefolia Blume and Q. serrata Thunb.ex Murray.

Specimens examined: KPM-NC0007439 (holotype), Izumino-mori, Yamato-shi, Kanagawa

pref., 21 Nov. 2000, coll. H.Takahashi; the same place, 25 Nov. 1999 coll. H. Takahashi; the

same place, 27 Nov. 1999, coll. H.Takahashi; the same place, 16 Nov.2000, coll. H. Takahashi.

Japanese name: Izumino-ashinagatake.

Notes: This species is characterized by its glabrous, violet-brown pileus and stipe, the

relatively large, distinctly amyloid basidiospores, the smooth, fusiform cheilocystidia, the

absence of pleurocystidia, the diverticulate pileipellis elements, and the absence of clamp

connections. These features suggest that this species belongs in the section Fragilipedes

(Fr.) Quel., as defined by Maas Geesteranus (Maas Geesteranus 1980, 1988a).

Mycena mustea Har.Takah. is most similar to M. fonticola, but differs in forming a pale

grayish purple pileus with low and broad umbo, clavate cheilocystidia apically with several

short digitate excrescences, and non-diverticulate elements in the stipitipellis.