Atheniella rutila Q. Na & Y.P. Ge, 2021

Ge, Yupeng, Liu, Zewei, Zeng, Hui, Cheng, Xianhao & Na, Qin, 2021, Updated description of Atheniella (Mycenaceae, Agaricales), including three new species with brightly coloured pilei from Yunnan Province, southwest China, MycoKeys 81, pp. 139-164 : 139

Atheniella rutila Q. Na & Y.P. Ge sp. nov.

Figs 2m-p , 5 , 6.

Diagnosis.

Pileus campanulate to hemispherical, concave with age, slightly pruinose. Lamellae adnate to adnexed, white. Stipe base with dense white fibrils. Basidiospores cylindrical, inamyloid. Pleurocystidia similar to cheilocystidia, fusiform, with a long neck. Pileipellis covered with numerous excrescences. Hyphae of the stipitipellis with simple cylindrical excrescences. Caulocystidia not seen. All tissues non-reactive in iodine. Clamps absent.

Holotype.

China. Yunnan Province, Lincang City, Wulaoshan National Forest Park, 31 Jul 2020, Qin Na, Yupeng Ge and Zewei Liu, FFAAS0354 (Collection No. MY0210).

Etymology.

Refers to the bright red-tinted pileus.

Description.

Pileus 2.0-10.2 mm in diam., campanulate to hemispherical, applanate or slightly concave at centre when old, deep salmon (10A7) to bright red (10A8), shallowly sulcate, translucent-striate, delicately pubescent, glabrescent when old. Context white, thin, very fragile. Lamellae broadly adnate to adnexed, ascending, white, concolorous with the sides, basally interveined with age. Stipe 5.0-15.8 × 1.0-2.0 mm, cylindrical, hollow, fragile, transparent, pruninose, glabrescent when old, base slightly swollen, covered with dense white fibrils. Odour and taste indistinctive.

Basidiospores [60/3/2] (7.2) 7.7- 8.6 -9.8 (10.1) × (3.6) 4.1- 4.6 -5.3 (5.5) μm [Q = 1.71-2.05, Q = 1.85 ± 0.079] [holotype [40/2/1] (7.2) 7.5- 8.5 -9.7 (10.0) × (3.6) 4.1- 4.6 -5.2 (5.5) μm, Q = 1.72-1.99, Q = 1.86 ± 0.086], narrowly ellipsoid to cylindrical, hyaline in water and 5% KOH, inamyloid, smooth. Basidia 19-28 × 5-8 μm, 2-spored, clavate, hyaline. Cheilocystidia 32-45 × 8-11 μm, abundant, fusiform, with a long neck, thin-walled and hyaline. Pleurocystidia similar to cheilocystidia, 27-42 × 7-12 μm. Pileipellis hyphae 2-5 μm wide, covered with numerous excrescences, 3.2-6.9 × 0.8-1.7 μm, hyaline. Hyphae of the stipitipellis 2-7 μm wide, non-dextrinoid, hyaline, with simple cylindrical excrescences, 4.6-14.3 × 2.9-5.2 μm. All tissues non-reactive in iodine. Clamps absent in all tissues.

Habit and habitat.

Scattered on rotten wood in evergreen broadleaf and Pinus mixed forest.

Other specimens examined.

Yunnan Province, Puer City, Xiaoheijiang National Forest Park, 1 Aug 2020, Qin Na, Yupeng Ge and Zewei Liu, FFAAS0356 (Collection No. MY0235).

Remarks.

Atheniella rutila is considered to be a distinct species in Atheniella on account of the bright red pileus, white stipe, narrowly ellipsoid to cylindrical and inamyloid spores and characters of the cystidia, pileipellis and stipitipellis ( Maas Geesteranus 1980, 1990, 1992a, b; Perry 2002; Grgurinovic 2003; Robich 2003; Aravindakshan and Manimohan 2015; Aronsen and Læssøe 2016). Atheniella amabillissima is difficult to distinguish from A. rutila owing to the reddish basidiomata, but the pileus of A. amabillissima fades to white with age or has a dirty yellowish disc, and the spores are smaller (7-9 × 3-4 μm) ( Smith 1935b). Atheniella adonis shows certain morphological similarities to A. rutila in possessing tiny and pinkish-red basidiomata, white lamellae and cylindrical basidiospores. However, A. adonis differs in producing a pileus with a white margin, longer stipe and clavate to fusiform caulocystidia ( Perry 2002; Robich 2003; Aronsen and Læssøe 2016). In comparison with Atheniella rutila , Mycena rohitha (≡ A. rohitha ) and M. wubabulna (≡ A. wubabulna ) have gelatinous pileus hyphae and narrower basidiospores ( Grgurinovic 2003; Aravindakshan and Manimohan 2015).

Figures

Figure 2. Basidiomata of Atheniella species a-c Atheniella adonis (Bull.) Redhead, Moncalvo, Vilgalys, Desjardin & B. A. Perry d-f Atheniella aurantiidisca (Murrill) Redhead, Moncalvo, Vilgalys, Desjardin & B. A. Perry g-i Atheniella flavida Q. Na & Y. P. Ge j-l Atheniella flavoalba (Fr.) Redhead, Moncalvo, Vilgalys, Desjardin & B. A. Perry m-p Atheniella rutila Q. Na & Y. P. Ge q-s Atheniella taoyao Q. Na & Y. P. Ge. Scale bars: 10 mm (a-f, j-l, n-p), 5 mm (g-i, q-s). Photographs a, b, d-h, j-o, q, r by Qin Na; c, i, p, s by Yupeng Ge.

Figure 5. Microscopic features of Atheniella rutila (FFAAS 0354, holotype) a-c basidiospores d basidia e, f cheilocystidia g, h pleurocystidia i pileipellis j stipitipellis. Scale bars: 10 μm (a-j).

Figure 6. Morphological features of Atheniella rutila (FFAAS 0354, holotype) a basidiomata b pleurocystidia c basidia d basidiospores e cheilocystidia f stipitipellis g pileipellis. Scale bars: 5 mm (a); 10 μm (b-g). Drawings by Qin Na and Yupeng Ge.