Mycena yuezhuoi Z.W. Liu, Y.P. Ge & Q. Na, 2021

Liu, Zewei, Na, Qin, Cheng, Xianhao, Wu, Xiaoming & Ge, Yupeng, 2021, Mycena yuezhuoi sp. nov. (Mycenaceae, Agaricales), a purple species from the peninsula areas of China, Phytotaxa 511 (2), pp. 148-162 : 153-159

Mycena yuezhuoi Z.W. Liu, Y.P. Ge & Q. Na sp. nov. ( Figs. 2 , 3 , 4 )

MycoBank No. MB 838747

Diagnosis:— Pileus purple and hygrophanous. Lamellae white, emarginate. Basidiospores elongated ellipsoid to cylindrical, (6.1)6.4–7.8(8.1) × (3.1)3.4–4.2(4.4) μm. Cheilocystidia obclavate to digitate altogether ± ventricose rostrate, obtuse apex, sometimes with cylindrical protrusions. Pileipellis and stipitipellis hyphae smooth.

Etymology:—Refers to the purple basidiomata, ‘yuezhuo’ is a purple, Chinese mythical creature symbolizing moral steadfastness.

Type:— CHINA. Shandong Province: Kunyushan National Nature Reserve, Yantai City , N37°15.7140′, E121°42.8104′, 21 August 2019, Zewei Liu, Yupeng Ge and Qin Na, FFAAS 0345 (Holotype!) .

Description:— Pileus 17–24 mm in diam., hemispherical when young, paraboloid or campanulate with age, with obtuse umbo or occasionally slightly depressed at center, grayish lilac (15B2–3), dull lilac (15C3–5) to dark purple (14F5–6), edge whitish, dark ruby (12F4–6) at the umbo with dull lilac (15C3) at first, then turning paler with age, pale purple (11E4–6) towards the margin, hygrophanous, dry, smooth, striate, shallowly sulcate, the margin sometimes undulate, slightly deflexed. Context pale grayish white (1B1), 1–3 mm thick, fragile. Lamellae emarginate, 21–26 reaching the stipe, close with 1–3 tiers of lamellulae, white, edge concolorous; intervenose, not easy to separate. Stipe 35–43 × 3.0–5.0 mm, central, cylindrical, the apex and base purplish brown (10F4–5), middle often paler to pale purplish brownish (10E4) when young, becoming dark brown (8F5–7) all over with age, fragile, hollow, silky, longitudinally striate, base slightly swollen, and whitely tomentose. Odor and taste raphanoid.

Basidiospores (140/7/4) (6.1)6.4– 7.1 –7.8(8.1) × (3.1)3.4– 3.8 –4.2(4.4) μm [Q = 1.70–2.04(2.14), Q = 1.87 ± 0.10] [holotype (40/2/1) (6.3)6.5– 7.1 –7.7(7.9) × (3.1)3.4– 3.8 –4.2(4.4) μm, Q = 1.70–2.04(2.07), Q = 1.86 ± 0.10], elongated pip-shaped to cylindrical, colorless, hyaline, smooth, thin-walled, amyloid. Basidia 19–31 × 4–7 μm, 4-spored, clavate, clamped, sterigmata 3.0–4.2 μm in length. Cheilocystidia 31–61 × 7–17 μm, abundant, obclavate to digitate altogether ± ventricose-rostrate, obtuse apex, sometimes with cylindrical protrusions, thin-walled, colorless, clamped, not mixed with basidia. Pleurocystidia absent. Pileipellis a cutis composed of cylindrical cells, 47–114 × 1–4 μm, smooth and thin-walled, clamped; terminal cells cylindrical, apically narrow, 21–38 μm in length, the apex 1–2 μm and base 3–4 μm in width. Hypodermium absent. Lamellar trama subcellular, dextrinoid. Stipitipellis a cutis composed of hyphae 2–6 μm diam., smooth, thin-walled, clamped; caulocystidia sparse towards stipe apex, absent in the middle and base of stipe, 34–47 × 9–13 μm, clavate and apically broadly rounded, thin-walled, smooth, clamped.

Habitat:—Scattered on the litter layer in Pinus , Quercus , and Robinia mixed forests.

Known distribution:— Shandong Province, China

Additional material examined:— CHINA. Shandong Province: Kunyushan National Nature Reserve, Yantai City , N37°15.7128′, E121°42.8140′, 21 August 2019, Zewi Liu, Yupeng Ge and Qin Na, FFAAS 0344 ; same location, N37°15.7233′, E121°42.5563′, 02 July 2020, Zewei Liu, Yupeng Ge, and Qin Na, FFAAS 0346 ; same location, 22 September 2020, Yupeng Ge and Qin Na, FFAAS 0347 .

Notes:—Following the classification of Maas Geesteranus (1980), M. yuezhuoi belongs to sect. Calodontes on account of its purple and hygrophanous pileus, white lamellae, and repent hyphae of the pileipellis. Among members of sect. Calodontes , M. diosma and M. pura are the most like M. yuezhuoi in macroscopic features. However, M. diosma is distinguished from M. yuezhuoi by having larger basidiospores [(6–)7.4–9.8 × 3.6–5.4 μm], various shapes of cheilocystidia, and several morphological characters, including a somewhat lubricous pileus when moist, adnexed and dark brownish violet to reddish violet lamellae, and a pruinose to pubescent apex of the stipe ( Robich 2003; Aronsen & Laessøe 2016). M. pura has abundant pleurocystidia, a glutinous pileus when wet, and is pruinose above the stipe; these characters distinguish this species from M. yuezhuoi ( Perry 2002; Robich 2003; Aronsen & Laessøe 2016; Na 2019). Maas Geesteranus (1992 a, 1992b) proposed that M. pura had seven colour forms based on material from the north temperate region. However, based on specimens of Malesia (tropical), Corner suggested the M. pura complex should contain four species ( Corner 1994). He thought the M. pura complex in Malesia should include M. decipiens ( Overeem 1926: 1) Métrod (1949: 85) , M. kuehneriana A.H. Sm. (1947: 190) , M. pearsoniana Dennis ex Singer (1959: 233) and M. pura which were distinguished based on the characteristics of pleurocystidia, lamellae and spores, and morphological descriptions ( Corner 1994). Compared with M. yuezhuoi , M. decipiens has smaller spores (mostly <7.5 μm in length) and cheilocystidia (<50 μm in length), and M. kuehneriana is only slightly intervenose or not at all. The distinguishing characteristics between other species in sect. Calodontes and M. yuezhuoi are shown in Table 3, 4.

*Features of other species that are clearly distinct from M. yuezhuoi are indicated in bold.

*Features of other species that are clearly distinct from M. yuezhuoi are indicated in bold.

More than half of the species in Mycena are known to lack pleurocystidia, and only 12 sections comprise species that all have pleurocystidia ( Smith 1947; Perry 2002; Grgurinovic 2003; Robich 2003; Aravindakshan & Manimohan 2015; Aronsen & Laessøe 2016; Na 2019). The presence of pleurocystidia is a common phenomenon in species of sect. Calodontes ; among them, M. pelianthina (Fr. 1821: 112) Quél. (1872: 102) , M. lammiensis Harmaja (1985: 44) , M. pura , M. rosea Gramberg (1912: 36) , and M. dura Maas Geest. & Hauskn. (1994: 5) have pleurocystidia that are like the cheilocystidia ( Aronsen & Laessøe 2016; Na 2019); M. clarkeana Grgur. (1997: 270) and M. vinacea Cleland (1931: 157) also have pleurocystidia ( Grgurinovic 2003). M. diosma , M. sirayuktha Aravind. & Manim. (2015: 79) , and M. nullawarrensis Grgur. (2003: 90) have few or no pleurocystidia ( Grgurinovic 2003; Aravindakshan & Manimohan 2015; Aronsen & Laessøe 2016). Pleurocystidia are absent in M. yuezhuoi , M. pearsoniana and M. subcorticalis (Cooke & Massee 1887: 93) Sacc. (1891: 35) ( Grgurinovic 2003; Aronsen & Laessøe 2016; Na 2019).

Finally, we note that the basidiospores of specimen FFAAS 0347 are relatively distinct. Q values of the spores from the other three specimens ranged from 1.70 to 2.14, whereas those of FFAAS 0347 varied from 1.78 to 2.52. We randomly measured 70 Q values of basidiospores in FFAAS 0347, mostly were in accordance with the other three specimens, but a few could measure up to 2.52.

Figures

FIGURE 2. a–c) Mycena yuezhuoi (FFAAS 0345) d) M. yuezhuoi (FFAAS 0344) e, f) M. yuezhuoi (FFAAS 0346) g, h) M. yuezhuoi (FFAAS 0347). Bars: a–c, e–h=10 mm, d=5 mm. Photos a–h by Qin Na.

FIGURE 3. Mycena yuezhuoi a, d) Basidiospores (FFAAS 0347); b, e) Basidiospores (FFAAS 0345); c) Cheilocystidia (FFAAS 0345); f, h) Stipitipellis and caulocystidia (FFAAS 0346); g) Lamellar trama (FFAAS 0345); i) Pileipellis with apically narrow terminal cells (FFAAS 0346). Bars a, b, d, e=5 μm; c, f–I =20 μm. Photos by Zewei Liu.

FIGURE 4. Mycena yuezhuoi (FFAAS 0345) a. Basidiomata; b. Basidia; c. Basidiospores; d. Cheilocystidia; e. Stipitipellis and caulocystidia; f. Pileipellis with apically narrow terminal cells. Bars a=1 cm; b, d, e, f=10 μm; c=5 μm Illustrations by Zewei Liu.