リュウキュウマツカサキノコ

Strobilurus luchuensis Har. Takah., Taneyama & Pham, in Takahashi, Taneyama, Kobayashi, Oba, E. Hadano, A. Hadano, Kurogi & Wada, The fungal flora in southwestern Japan, Agarics and boletes 1: 155 (2016)

リュウキュウマツの球果から発生し、スギエダタケに外観が類似したマツカサキノコ属（Strobilurus）の仲間です。

主な形態的特徴

ア）傘表面は白色, 微細な毛状.

イ）柄は帯褐色で根元に向かって白色の剛毛～長軟毛に被われる.

ウ）担子胞子は無色, 非アミロイド.

エ）縁シスチジアを欠く.

オ）側シスチジアはこん棒形～広こん棒形で通常頂部において偽アミロイドに染まる粗大な樹脂状結晶に被覆される.

カ） 傘表皮組織は狭紡錘形～毛状傘シスチジアが散在する子実層状被を形成する.

キ）柄シスチジアはやや厚壁でしばしば頂部頭状形になり, 長い毛状または円柱形～亜こん棒形.

ク）柄実質は厚壁の菌糸からなる.

コメント: 無色で非アミロイドの担子胞子, 粗大な樹脂状結晶が付着する側シスチジア, 子実層状被を成す傘表皮組織, 松毬から発生する生態は本種がマツカサキノコ属Strobilurus (Singer 1962) に位置することを示唆している.

本種の子実体の外観はマツカサキノコモドキStrobilurus stephanocystis (Kühner & Romagn. ex Hora) Singer (Singer 1962; Redhead 1980; Bas et al. 1999) およびスギエダタケStrobilurus ohshimae (Hongo) Hongo (Hongo 1955, 1989; Katumoto 2010) にやや類似するが, マツカサキノコモドキは通常傘が有色で, 柄は白色粉状を呈し, 厚壁で小のう形のシスチジアが子実層に存在し, 毛状の柄シスチジアを持たない. またスギエダタケは厚壁な縁シスチジアおよび頂部頭状形の傘シスチジアを有し, 通常スギまたはヒノキの落枝上から発生する.

　生態および発生時期: 落下したリュウキュウマツの球果上に孤生または散生, 11月～1月, 普通種.

分布: 八重山諸島 （石垣島, 西表島).

Habitat and phenology: Solitary or scattered on fallen or buried strobili of P. luchuensis Mayr., November to January, common.

Known distribution: Okinawa (Ishigaki Island and Iriomote Island).

Holotype: TNS-F-52278, on fallen or buried strobili of P. luchuensis. Ishigaki-shi, Okinawa, 14 Nov. 2012, coll. Takahashi, H.

GenBank accession number: AB968234 (ITS).

Japanese name: Ryukyu-matukasakinoko (named by Y. Terashima).

Comment: The colorless, inamyloid basidiospores, the pleurocystidia encrusted with coarse, resinous crystals, the hymeniform pileipellis, and the habitat on strobili suggest the present fungus belongs to the genus Strobilurus Singer (Singer 1962).

Strobilurus luchuensis is macromorphologically similar to Strobilurus stephanocystis (Kühner & Romagn. ex Hora) Singer, which is a well-defined European species (Singer 1962; Redhead 1980; Bas et al. 1999), and Strobilurus ohshimae (Hongo) Hongo from Japan (Hongo 1955, 1989; Katumoto 2010). Strobilurus stephanocystis differs in having a usually distinctly colored pileus, a white pruinose stipe, utriform hymenial cystidia with thickened walls and lacking piliform caulocystidia with warty protuberances. Strobilurus ohshimae is distinct in having thick-walled cheilocystidia, capitate pilocystidia, and a habitat of dead fallen twigs of Cryptomeria japonica (Thunb. ex L.f.) D.Don. and Chamaecyparis obtusa Sieb. & Zucc.

References 引用文献

Bas C, Kuyper Th W, Noordeloos ME, Vellinga EC, Crevel R (eds). 1999. Flora Agaricina Neerlandica - Volume 4 - Critical Monographs on Families of Agarics and Boleti Occurring in the Netherlands. Monographs on the Tricholomataceae (part 3), tribus Tricholomateae and tribus Xeruleae and on the family of Strophariaceae. Rotterdam.

Hongo T. 1955. Notes on Japanese larger fungi (6). J Jpn Bot 30 (3): 73–79.

Hongo T. 1989. Tricholomataceae. In: Imazeki R, Hongo T (eds), Colored illustrations of mushrooms of Japan I. Hoikusha, Osaka, pp 56–115 (in Japanese).

Katumoto K. 2010. List of Fungi Recorded in Japan. The Kanto Branch of the Mycological Society of Japan, Kyoto.

Singer R. 1962. New genera of fungi. VIII. Persoonia 2 (3): 407–415.

Redhead SA. 1980. The Genus Strobilurus (Agaricales) in Canada with Notes on Extralimital Species. Can J Bot 58: 68–83.

Yoshie Terashima (supervisor), Haruki Takahashi (editor), Yuichi Taneyama (editor). 2016. The fungal flora in southwestern Japan:　Agarics and boletes. Tokai University Press. 349p.