Inocybe squarrosolutea (Corner & E. Horak) Garrido, Bibliotheca Mycologica 120: 177, 1988.

Li, Sai Nan, Xu, Fei, Jiang, Ming, Liu, Feng, Wu, Fang, Zhang, Ping, Fan, Yu Guang & Chen, Zuo Hong, 2021, Two new toxic yellow Inocybe species from China: morphological characteristics, phylogenetic analyses and toxin detection, MycoKeys 81, pp. 185-204 : 185

Inocybe squarrosolutea (Corner & E. Horak) Garrido, Bibliotheca Mycologica 120: 177, 1988.

Figures 2 , 3 , 6a

Astrosporina squarrosolutea ≡ Astrosporina squarrosolutea Corner & E. Horak, Persoonia 10(2): 175, 1979.

Basidiomata.

Small to medium-sized. Pileus: 30-60 mm in diameter, bell-shaped to convex when young, and then planar with umbonate center; margin strongly in-rolled or deflexed when young, and then gradually straight when mature; center covered with stout, erect, conic squamules (up to 2 mm high, 1-1.5 mm wide), coarsely fibrillose towards the margin; surface dry, primrose yellow (1A6) to bright yellow (2A5), becoming pale brown (3B6) over the disc. Lamellae crowded (ca. 50-70), 3-5 mm wide, adnexed to adnato-decurrent, often subsinuate; light yellow (1A5) turning to pale yellow-fuscous (2B5), edge concolorous, even. Stipe 35-75 × 4-8 mm, cylindrical or attenuated towards apex, stout, base subbulbous to bulbous, up to 16 mm wide; bright yellow (2A5); apex pruinose, covered with bright yellow(2A5) to orange (2A6), longitudinal, floccose-fibrillose fibrils towards base; dry, solid. Cortina conspicuous present in young specimens. Context pale yellow (1A4) in stipe and cuticle.

Basidiospores.

(5.0) 5.5-9.0 (10.0) µm (av. 7.1 μm, SD 1.1 μm) × (4.0) 4.5-6.0 (6.5) µm (av. 5.3 μm, SD 0.6 μm), Q = (1.00) 1.11-1.67 (1.80), Qm = 1.33 ± 0.19 (n = 200 of 10 coll.), nodulose, 6-8 hemispheric knobs, yellow-brown with 5% KOH. Basidia: 17-26 × 7-9 µm, 4-spored, clavate to broadly clavate. Pleurocystidia: 37-67 µm (av. 46.1 μm, SD 3.0 μm) × 10-18 µm (av. 13.4 μm, SD 1.2 μm), Q = 2.80-4.0 (n = 100 of 10 coll.), abundant, broadly fusoid to lageniform; crystalliferous at apex, base usually truncate to obtuse, occasionally tapered into pedicel; metuloid, hyaline, sometimes contain a few small crystals or resinous inclusions, thick-walled, walls up to 1.5 µm thick, bright yellow with 5% KOH. Cheilocystidia similar to pleurocystidia, 35-62 × 9-17 µm; paracystidia: 12-25 × 5-11 µm, abundant, thin-walled, translucent inside, clavate to broadly clavate. Hymenophoral trama: sub-regularly arranged, yellowish with 5% KOH, composed of thin-walled, cylindrical to inflated hyphae 4-23 µm wide. Caulocystidia: 48-98 × 17-22 µm, present at stipe apex, in clusters, similar to those of hymenial cystidia; cauloparacystidia: 20-35 × 10-13 µm, clavate to broadly clavate, thin-walled, nearly hyaline inside, abundant. Pileipellis a trichoderm, regular to subregular, pale brown with 5% KOH, composed of smooth, thin-walled, cylindrical hyphae, 4-8 µm in diameter. Oleiferous hyphae present in pileus and stipe trama, 3-10 µm in diameter, branched. Clamp connections present and common in all tissues.

Habitat.

Single to scattered in mixed forest dominated by Pinus and Quercus .

Known distribution.

Malaysia (type location) ( Horak 1979), China (Hunan Province, Anhui Province).

Specimens examined.

China, Hunan Province: Yongshun County, 29 July 2015, MHHNU8536; Yizhang County, 16 September 2016, MHHNU8984; Ningyuan County , 28 May 2017, MHHNU31006; Youxian County , 9 June 2017, MHHNU31042; 18 June 2019, MHHNU31445; Guidong County , 6 July 2018, MHHNU31173; Yongzhou City , 22 May 2019, MHHNU31427; 11 June 2020, MHHNU31875; Qidong County , 2 June 2019, MHHNU31434 ; Anhui Province, Huangshan City , 11 Aug. 2020, MHHNU32151 .

Figures

Figure 2. Basidiomata of Inocybe squarrosolutea a, b MHHNU 8536 c MHHNU 31006, and d MHHNU 31427. Scale bars: 10 mm.

Figure 3. Microscopic features of Inocybe squarrosolutea (MHHNU 31427) a basidiospores b basidia with probasidium c gill edge d cheilocystidia and paracystidia e pleurocystidia f caulocystidia and cauloparacystidia g, h pileipellis i oleiferous hyphae, and j hymenial hyphae. Scale bars: 10 µm.

Figure 6. SEM images showing basidiospores of a Inocybe squarrosolutea b Inocybe squarrosofulva. Scale bars: 5 µm.