シコンサクラタケ (紫紺桜茸）

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

全体に暗紫色を帯び, モリノカレバタケ型に似たやや肉厚な子実体を形成します。サクラタケの仲間に似ていますが、表皮組織の菌糸細胞が分岐物を持ち、シスチジアの類型がサクラタケ亜節(Sect. Calodontes Subsect. Purae)と異なり、アクニオイタケ節 (Sect. Fragilipedes)に分類されています。

肉眼的特徴: 傘は径 10-25 mm, 最初釣り鐘形, のちやや饅頭形に平開し, 時に中央部がや

やへそ状に凹み, 放射状の溝線を表し, やや吸水性, 半透明の条線を表し, 乾性, 初め白色粉

状, のち平滑になり, 中央部は暗紫色 (紫紺色, RGB値＝ #411445), 周縁部に向かってやや退

色する.　肉は傘の中央部において厚さ 0.5 mm 以下, 白色, 特別な味や臭いはない. 柄は 30-

40×1-3 mm, 円柱形, 中心生, やせ型, 時にやや偏圧され, 中空, 乾性, 全体に白色粉状, 傘よ

りやや淡色, 根本は白色の剛毛状菌糸体に被われる. ヒダは直性し, 疎 (柄に到達するヒダは

(15-19), 幅 2.5 mm以下, 傘よりやや淡色, 縁部は側面より淡色または類白色.

顕微鏡的特徴: 担子胞子は 8-9×5-6μm, 広楕円形, 表面は平坦, 無色, アミロイド, 薄壁.

担子器は 40-60×10-12 μm, こん棒形, 4胞子性. 縁シスチジアは 30-45×10-17μm, 群生

し, こん棒形, 通常頂部に数個の瘤状分岐物を具え, 無色, 薄壁. 側シスチジアを欠く. 子実層

托実質の菌糸は細胞内に褐色の色素を持ち, 偽アミロイド. 傘の上表皮層の菌糸は匍匐性で,

幅 2-6μm, 平行に配列し, 円柱形, 平坦または疣状分岐物が散在し, 無色または淡褐色, 偽ア

ミロイド, 薄壁. 上表皮下層の菌糸は無色または褐色, 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分岐物が散在し, 褐色, 偽アミロイド; 柄

シスチジアは 45-88×5-8 μm, 円柱形, 複数の瘤状～短指状分岐物に被われ, 無色または

褐色, 薄壁. 傘と柄の表皮組織, 及び子実層托実質の菌糸にクランプが存在する.

供試標本: KPM-NC0008701 (holotype), Maruyama, Iriuda, Odawara-shi, Kanagawa pref., 4

Jun. 2000, coll. H.Takahashi; the same place, 27 Jun. 2001, coll. H. Takahashi; the same

place, 17 Sept. 2001, coll. H.Takahashi.

コメント: 全体に暗紫色を帯び, モリノカレバタケ型に似たやや肉厚な子実体を形成し, 通常

頂部に複数の瘤状分岐物を具えたこん棒形の縁シスチジアを有し, 側シスチジアを欠き, 数個

の瘤状～短指状分岐物に被われた円柱形の柄シスチジアが存在する. 六月～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.

アミロイドの担子胞子, 数個の頂生分岐物に被われた縁シスチジア, そして多分枝菌糸型

の柄シスチジアを有する性質に基づき, 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) に属すると考えられる.

Cerasinae 節に属するブラジル産 Mycena cerasina Maas G. & de Meijer (Maas and

Meijer 1997) は本種に似た性質を示すが, 傘と柄は灰紫色を帯び, 縁シスチジアは平坦で分

岐物を欠く. アカバシメジ節サクラタケ亜節 (sect. Calodontes, subsect. Purae) に属する欧州

産 Mycena diosma Krieglst. & Schwobel (Courtecuisse and Duhem 1994; Moser and Julich

1999; Maas 1989; Robich 2003)も子実体の色と類型において本種に類似するが, 紡錘形の縁

シスチジアと側シスチジアを有し, 傘と柄の表皮組織は多分枝菌糸を欠く.

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

Etymology: From Latin, clari- (clear-) ＋ violacea (violaceous).

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

age, sometimes shallowly umbilicate, radially sulcate-striate almost to the disk,

subhygrophanous, dry, minutely white pruinose when young, soon becoming glabrous, at first

dark violet (15F6-7 to 16F6-7) overall, fading to greyish violet (15E5-6 to 16E5-6) from the

margin with age. Flesh up to 0.5 mm, whitish; odor and taste not distinctive. Stipe 30-40×1-

3 mm, cylindrical, central, slender, terete or compressed, hollow, dry, minutely white pruinose

over the entire length, entirely greyish violet (15E5-6 to 16E5-6) to dark violet (15F6-7 to

16F6-7); base covered with white, strigose mycelial tomentum. Lamellae adnate, distant (15-

19 reach the stipe), up to 2.5 mm broad, thin, paler concolorous with the pileus; edges

whitish or paler.

Basidiospores (n = 65 spores of 7 basidiocarps) 8-9×5-6 μm, Q (length/breadth) = 1.5-

1.6, broadly ellipsoid, smooth, colorless, amyloid, thin-walled. Basidia 40-60×10-12 μm,

clavate, four-spored. Basidioles clavate. Cheilocystidia 30-45×10-17 μm, abundant,

forming a sterile lamella edge, clavate, apically with one or more, knob-like short

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

element hyphae 12-21 μm wide, cylindrical, often somewhat inflated, thin-walled, smooth,

with cytoplasmic brownish pigment, dextrinoid. Pileipellis a cutis of parallel, repent hyphae 2-

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

walls thin, colorless or pale brownish, dextrinoid; underlying hyphae parallel, cylindrical,

hyaline or brownish, dextrinoid, with short and inflated cells up to 48 μm wide. Stipitipellis a

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

warty or finger-like diverticulae, brownish, dextrinoid, thin-walled; caulocystidia 45-88×5-8

μm, cylindrical, diverticulate, colorless or brownish, thin-walled. Stipe trama composed of

longitudinally running, cylindrical hyphae 8-25 μm wide, smooth, colorless, dextrinoid. Clamp

connections present in the pileipellis, the stipitipellis, the hymenophoral trama, and at the

basal septa of basidia.

Known distribution: Japan (Kanagawa).

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

to September.

Specimens examined: KPM-NC0008701 (holotype), Maruyama, Iriuda, Odawara-shi,

Kanagawa pref., 4 Jun. 2000, coll. H.Takahashi; the same place, 27 Jun. 2001, coll. H.

Takahashi; the same place, 17 Sept. 2001, coll. H.Takahashi.

Japanese name: Shikon-sakuratake.

　 Notes: Distinctive features of this species are found in its medium-sized, in part collybioid,

dark violet basidiomata, the amyloid basidiospores, the clavate cheilocystidia covered with

one or more, knob-like, apical excrescences, the absence of pleurocystidia, and the

cylindrical, diverticulate caulocystidia.

　 Its amyloid basidiospores, the cheilocystidia covered with one or more, knob-like, apical

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

diverticulate caulocystidia suggest placement of this taxon in the section Fragilipedes (Fr.)

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

Mycena clariviolacea appears to be closely related to M. cerasina Maas Geest. & de

Meijer, described from Brazil (Maas Geesteranus and Meijer 1997), and European M. diosma

Krieglst. & Schwobel (Maas Geesteranus 1989; Courtecuisse and Duhem 1994; Moser and

Julich 1999; Robich 2003). Mycena cerasina, which belongs in the section Cerasinae Maas

Geest. & de Meijer, differs in having a grayish purple pileus and stipe, and forming

subutriform to sublageniform, smooth cheilocystidia. Mycena diosma, which belongs in the

section Calodontes (Fr. ex Berk.) Quel. subsection Purae (Konr. & Maubl.) Maas Geest., is

distinct in having smooth, fusiform cheilocystidia and pleurocystidia, and non-diverticulate

elements in the cortical layer of pileus and stipe.