ヤミイロクヌギタケ

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

傘は暗褐色を帯び、基質上にしばしば白色の紐状菌糸束を伴い、ヒダは明瞭な連絡脈を形成します。発生が稀なキノコです。

オーストラリア南部に分布するMycena nargan Grgur. (1995)は外観的特徴がヤミイロクヌギタケに似ていますが、幼菌は白色鱗片状の被膜に被われると言われています。 https://wikiwand.com/en/Mycena_nargan…

肉眼的特徴: 傘は径 10-25 mm, 最初釣り鐘形, のち中高の平らに平開し, 中央部に不規則

な凹凸を表し, 湿時半透明の条線を表し, 吸水性, 乾性, 初め白色粉状, のち平滑になり, 中央

部は暗褐色, 周縁部に向かって退色する.　肉は傘の中央部において厚さ 1 mm 以下, 白色,

特別な味や臭いはない. 柄は 40-50×1.5-2 mm, 円柱形, 根本が僅かに拡大し, 中心生, やせ

型, 中空, 乾性, 全体に白色粉状, 類白色の頂部以外は褐色～暗褐色を帯び, 根本は白色の

綿毛状菌糸体に被われ, しばしば基質上に白色の紐状菌糸束を形成する. ヒダは直性し, 疎

(柄に到達するヒダは 15-18), 幅 2.5 mm以下, 淡灰色, 明瞭な連絡脈を形成し, 縁取りを欠く.

顕微鏡的特徴: 胞子紋は純白色. 担子胞子は 8-11×5-6 μm, 楕円形, 表面は平坦, 無

色, 非アミロイド, 薄壁. 担子器は 28-35×7-8 μm, こん棒形, 2-4胞子性. 縁シスチジアは 30-

45×10-15 μm, 群生し, こん棒形, 頂部に 2 -4個の円柱形～瘤状分岐物を具え, 無色, 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, 細胞内に褐色の色素が存在す

る. 傘の上表皮層の菌糸は匍匐性で, 幅 3-10μm, 平行に配列し, 円柱形, 疣状～短指状突起

に被われ, 無色, 薄壁. 上表皮下層の菌糸は細胞内に褐色の色素を持ち, 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. 柄表皮の菌糸は平坦または疣状～短指状突起に被われ, 無色;

柄シスチジアは45-60×4-8 μm, 円柱形, 疣状～短指状突起に被われ, 無色, 薄壁 . 柄の実

質は細胞内に褐色の色素を持ち, 偽アミロイド. 柄の組織及び偽担子器の根元にクランプが存

在する.

供試標本: KPM-NC0008695 (holotype), Maruyama, Iriuda, Odawara-shi, Kanagawa pref.,

15 Sept. 2000, coll. H.Takahashi; KPM-NC0008696, the same place, 27 Apr. 2001, coll. H.

Takahashi; KPM-NC0008697, the same place, 3 May 2001, coll. H.Takahashi.

Japanese name: Yamiiro-kunugitake.

コメント:モリノカレバタケ型に似たやや肉厚な子実体を形成し, 傘と柄は暗褐色を帯び、ヒダ

は明瞭な連絡脈を表し, しばしば基質上に白色の紐状菌糸束を形成し, 担子胞子は非アミロイ

ド, 縁シスチジアはこん棒形で頂部に 2-4個の円柱形～瘤状分岐物を具え、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, 柄の組織及び偽担子器の根元にクランプが存

在する. 五月～九月, 神奈川県小田原市入生田の照葉樹林内の落枝上に発生. 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.

本種は非アミロイドの担子胞子, 多分枝菌糸からなる傘の表皮組織, そして暗色の色素を

持つ実質の性質に基づき, Maasの分類概念 (Maas 1980, 1991) によるウスズミコジワタケ節

(section Hiemales ) に属すると考えられる. 本種は欧州産 Mycena flosnivium Kuhner

(Breitenbach and Kranzlin 1991; Kuhner 1938; Maas 1985; Robich 2003) に似るが, 欧州産種

はアミロイドの担子胞子を持ち, ヒダに連絡脈を欠き, 基質上に紐状菌糸束を形成しない.

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

Etymology: From Latin, nidificata = nidificate.

Pileus 10-25 mm in diam, at first conico-convex to campanulate, then plano-convex in

age, center somewhat irregularly rugulose to pitted, less so toward the sulcate-striate

margin, hygrophanous, dry, minutely white pruinose at first, soon becoming glabrous, almost

blackish brown at the center, dark brown (7F5-7 to 8F5-7) to reddish brown (8E4-6)

farther outward, much paler at the margin, occasionally evenly colored dark brown (7F5-7

to 8F5-7). Flesh up to 1 mm, white; odor and taste not distinctive. Stipe 40-50×1.5-2 mm,

cylindrical, slightly enlarged at the base, central, slender, terete, hollow, dry, white pruinose

over the entire length from the outset, not glabrescent with age, pale brownish at the apex,

dark brown (7F5-7 to 8F5-7) toward the base; base covered with white mycelial tomentum

attached to an white cord-like rhizomorphs on the substratum. Lamellae adnate, distant (15

-18 reach the stipe), up to 2.5 mm broad, thin, grayish, distinctly intervenose; edges

concolorous.

Basidiospores (n = 73 spores of 15 basidiocarps) 8-11×5-6 μm, Q (length/breadth) =

1.6-1.8, short ellipsoid to ellipsoid, smooth, colorless, inamyloid, thin-walled. Basidia 28-35×7

-8 μm, clavate, mostly four-spored. Basidioles clavate. Cheilocystidia 30-45×10-15 μm,

abundant, forming a sterile lamella edge, clavate, with several irregularly cylindrical to knob-

like apical appendages 3-11×2-5 μm, colorless, thin-walled. Pleurocystidia absent.

Hymenophoral trama regular; element hyphae 6-26 μm wide, cylindrical, often inflated, thin-

walled, smooth, with cytoplasmic brownish pigment, dextrinoid. Pileipellis a cutis of parallel,

repent hyphae 3-10 μm wide, cylindrical, smooth or covered with scattered, warty or finger

-like diverticulae, walls thin, colorless; underlying hyphae parallel, with cytoplasmic brownish

pigment, dextrinoid, with short and inflated cells up to 40 μm wide. Stipitipellis a cutis of

parallel, repent hyphae 3-8 μm wide, cylindrical, smooth or covered with scattered, warty

or finger-like diverticulae, colorless, inamyloid or dextrinoid, thin-walled; caulocystidia 45-60

×4-8 μm, infrequent, cylindrical, diverticulate, colorless, thin-walled. Stipe trama

composed of longitudinally running, cylindrical hyphae 10-25 μm wide, smooth, with

cytoplasmic brownish pigment, dextrinoid. Clamp connections present in the stipe tissues

and at the basal septa of basidia.

Known distribution: Japan (Kanagawa).

　 Habitat: Solitary or scattered, on dead fallen twigs in Quercus-Castanopsis forests, May

to September.

Specimens examined: KPM-NC0008695 (holotype), Maruyama, Iriuda, Odawara-shi,

Kanagawa pref., 15 Sept. 2000, coll. H.Takahashi; KPM-NC0008696, the same place, 27 Apr.

2001, coll. H. Takahashi; KPM-NC0008697, the same place, 3 May 2001, coll. H.Takahashi.

Japanese name: Yamiiro-kunugitake.

　 Notes: Distinctive features of this species are found in its dark brown pileus and stipe,

the distinctly intervenose lamellae, the white cord-like rhizomorphs on the substratum;

microscopically the inamyloid basidiospores, the clavate cheilocystidia with digitate apical

appendages, the diverticulate elements in the cortical layer of pileus and stipe, and the

presence of clamp connections are characteristic.

　　The inamyloid basidiospores, the diverticulate pileipellis elements, and the dark pigment in

the tramal elements suggest placement of this taxon in the section Hiemales Konrad &

Maubl. (Maas Geesteranus 1980, 1991). Because of its medium-sized, in part collybioid

basidiomata, the white cord-like rhizomorphs, and its distinctly intervenose lamellae, it

seems to have an isolated position within the section.

Mycena granulifera Maas Geest.& de Meijer, described from Brazil (Maas Geesteranus

and Meijer 1997), is comparable to M. nidificata in having inamyloid basidiospores, clavate

cheilocystidia with digitate excrescences, and diverticulate pileipellis elements. The former

species, however, differs in forming a whitish, rugulose pileus and clavate subfusiform

pleurocystidia. Mycena nidificata also bears some resemblance to European M. flosnivium

Kuhner (Kuhner 1938; Maas Geesteranus 1985; Breitenbach and Kranzlin 1991; Robich

2003) which differs in having cylindrical, amyloid basidiospores, non-intervenose lamellae,

and lacking cord-like rhizomorphs.