ツバナシツチナメコ

Agrocybe pseudoerebia Har. Takah., Mycoscience 42: 355-360, 2001　

地上生で、消失性のやや厚い縁片膜を持ち、ツバを形成しません。

外観がよく似たハゴロモイタチタケとしばしば混同されています。

肉眼的特徴: 傘は径 15-30 mm, 最初饅頭形, のち平開し, 時に中丘があり, 平坦, 平滑, 乾

性, 吸水性, 湿時半透明の条線を表し, 湿時褐色 (中央部は濃色), 乾燥すると周縁から退色

し, 幼時白色で消失性の縁片膜を有する. 肉の厚さは 2 mm以下, 傘と同色, 特別な味や臭

いはない. 柄は 30-80×2-4 mm mm, ほぼ上下同大, 中心生, 痩せ型, 中空, ツバを欠き, 類白

色, 繊維状, 根本は白色の密綿毛状菌糸体に被われる. ヒダは上生し, 密 (柄に到達するヒダ

は 27-31), 幅 5 mm以下, 傘と同色; 縁部は長縁毛状 (fimbriate), 縁取りを欠く.

顕微鏡的特徴: 担子胞子は 7.5-8.5×3.5-4.5μm [Q = length/breadth: 1.89-2.14], 楕円形,

表面は平坦, 褐色, 厚壁. 担子器は 40-50×10-12 μm, こん棒形, 3-4胞子性. 縁シスチジア

は 20-50×7-13μm, 群生し, フラスコ形～片脹れ状で伸長した嘴状突起 (rostrum) を有し, 平

坦, 無色, 薄壁. 側シスチジアはない. 子実層托実質は平列型, 菌糸は傘実質に似るが, 無色.

傘表皮の菌糸は子実層状被を形成し, 20-70×10-28 μm, こん棒形～洋梨形, 帯褐色, 厚壁

(0.5μm). 被膜 (縁片膜) を構成する菌糸細胞は 10-50×4-10 μm, 不規則に錯綜し, 円柱

形, 肥大せず, しばしば分岐し, 無色, 平坦, 薄壁, 時にクランプを有する. 柄シスチジアは 15-35

×5-10μm, 柄の上部に散生し, こん棒形～類円柱形, 無色, 薄壁. 柄の表皮と実質, そして被

膜 (縁片膜) にクランプが見られる.

供試標本: KPM-NC0007435 (基準標本), Izumino-mori, Yamato-shi, Kanagawa-ken, 19

Nov. 1999, H.Takahashi; KPM-NC0007436, the same place, 30 Oct. 2000, H.Takahashi.

コメント: 子実体はツバを欠き, 消失性の縁片膜を有し, 胞子は長さ 10 um以下で発芽孔を

欠く. 神奈川県大和市泉の森のマテバシイとコナラを中心とする林内地上に発生. 標本は神

奈川県立生命の星・地球博物館の標本庫(KPM)に登録, 収蔵されている.

Agrocybe pseudoerebia Har. Takah., Mycoscience 42: 355-360, 2001　　　　　

Pileus 15-30 mm in diam, at first convex, expanding to plane, sometimes broadly

umbonate, smooth, glabrous, dry, hygrophanous, translucent-striate when moist, brown (7D7-

8) when moist, mottled with darker areas (near brown: 7F7-8) at the center, drying to paler

(6D7-8) from the margin, with white, fugacious, flocculose veil remnants hanging from the

margin. Flesh up to 2 mm, concolorous with the pileus; odor and taste not distinctive. Stipe

30-80×2-4 mm, almost equal, central, slender, terete, solid, whitish, fibrillose, without an

annulus; base covered with white mycelial tomentum. Lamellae adnexed, close (27-31 reach

the stipe), up to 5 mm broad, concolorous with the pileus; edges fimbriate, concolorous.

Basidiospores 7.5-8.5×3.5-4.5 μm [Q = length/breadth: 1.89-2.14], ellipsoid, smooth,

brown, thick-walled, without a germ pore. Basidia 40-50×10-12 μm, clavate, three- to four

-spored. Cheilocystidia 20-50×7-13 μm, abundant, lageniform to ventricose with an

elongated rostrum, smooth, colorless, thin-walled. Pleurocystidia absent. Hymenophoral

trama regular; element hyphae similar to those of the pileitrama but colorless. Pileipellis

hymeniform, consisting of clavate to pyriform cells 20-70×10-28 μm, with brownish,

thickened walls (up to 0.5 μm). Hyphae of pileitrama 5-30 μm wide, parallel, cylindric, often

inflated, branched, with incrusting, brown pigment, with brownish, thickened walls (up to 0.5 μ

m). Elements of veil remnants 10-50×4-10 μm, irregularly entangled, cylindric, not inflated,

often irregularly branched, colorless, smooth, thin-walled, occasionally with clamped septa.

Stipitipellis a cutis of parallel, repent hyphae up to 10 μm wide, cylindric, colorless, thin-

walled, occasionally with clamped septa; caulocystidia 15-35×5-10 μm, scattered on the

stipe apex, clavate to subcylindric. Stipe trama composed of longitudinally running, cylindric

hyphae up to 17μm wide, unbranched, colorless, thin-walled, occasionally with clamped

septa.

Known distribution: Japan (Kanagawa).

Habitat: Solitary to scattered on ground in broad-leaved forest dominated by Pasania

edulis and Quercus serrata, October to November, not common.

Specimens examined: KPM-NC0007435 (holotype), Izumino-mori, Yamato-shi, Kanagawa-

ken, 19 Nov. 1999, H.Takahashi; KPM-NC0007436, the same place, 30 Oct. 2000, H.

Takahashi.

Japanese name: Tsubanashi-tsuchi-nameko.

Notes: This species is characterized by the absence of a membranous annulus, the

fugacious veil remnants around the pileal margin, the relatively shorter basidiospores (less

than 10 μm long) without a germ pore, and the terrestrial habitat. The absence of a germ

pore and the terrestrial habitat suggest that this species is a member of the section

Velatae Singer in the subgenus Aporus Singer (Singer, 1986). Agrocybe pseudoerebia,

however, differs from other species of the section Velatae by its much shorter

basidiospores and the absence of a membranous annulus.

Agrocybe pseudoerebia is similar to European Agrocybe gibberosa (Fr.) Fayod

(Breitenbach and Kranzlin, 1995; Watling, 1982), which differs in having a browning stipe,

basidiospores with a prominent germ pore, clavate-vesicular cheilocystidia, and clavate to

lageniform pleurocystidia.