Russula latolamellata Y. Song & L. H. Qiu 2020, sp. nov.
Creators: name: Zhou, Songyan
name: Song, Yu
name: Chen, Kaixing
name: Li, Jingwei
name: Buyck, Bart
name: Qiu, Lihong
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Russulales
Russulaceae
Russula
Russula latolamellata

description: Russula latolamellata Y.Song & L.H.Qiu, sp. nov.
(Figs 3; 4)
MYCOBANK NUMBER. — MB 835726.
HOLOTYPE. — China. Guangdong Province, Zhaoqing City, Dinghushan Biosphere Reserve, on the ground in broadleaf forest, 6.IV.2015, J. B. Zhang K15060604 (GDGM 79561).
ETYMOLOGY. — Named after its broad lamellae.
DIAGNOSIS. — Mainly characterized by its distinctly cracking and black-tan pileus, broad and sparse lamellae, stipe and context becoming scarlet when bruised, basidiospores with completely reticulate ornamentations, common presence of 1-spored basidia, encrusted hyphae with brown pigments in pileipellis and absence of both pileocystidia and caulocystidia.
HABITAT AND DISTRIBUTION. — Solitary or gregarious in broadleaf forest.
ADDITIONAL SPECIMENS EXAMINED. — China. Guangdong Province, Zhaoqing City, Dinghushan Biosphere Reserve, on the ground in broadleaf forest, 13. IX. 2016, J. W. Li, Y. Song K16091311 (GDGM 79562); 13.VII.2015, J. W. Li, Y. Song K17071307 (GDGM 79563).
DESCRIPTION
Basidiomata
Medium to large sized, agaricoid.
Pileus
6-12 cm in diameter, hemispherical when young, becoming applanate with a slightly depressed center when mature; surface dry, cracking, tan, grayish to blackish brown, not easy to peel; margin entire or undulate.
Lamellae
Adnate, sparse, up to 8 mm broad, irregularly unequal, sometimes forked near stipe or at pileus margin, sometimes interveined; surface smooth, white, off-white to cream, tinged with reddish brown; lamella edge concolorous.
Stipe
4-8 cm long, central, cylindrical, sometimes tapering upwards or downwards, longitudinally rugulose, white to off-white, becoming grayish white when old, turning reddish-brown to scarlet when bruised, solid or stuffed.
Context
White, becoming reddish-brown when bruised, turning yellowish-brown in reaction with 5% FeSO 4.
Odour
Slightly unpleasant.
Taste
Mild.
Spore print
White.
Basidiospores
Subglobose to ellipsoid, [100/5/3] (5.9-) 6-6.8-7.4 (-7.5) × (4.9-) 5.1-5.8-6.5 (-6.9) µm, Q = (1.04-) 1.06-1.17-1.32 (-1.37); ornamentations amyloid, composed of low ridges, forming a complete reticulum; suprahilar spot inamyloid.
Basidia
41-60 × 6-12 µm, clavate to narrowly clavate, 1-, 2-, 3- or 4-spored, hyaline or containing oil droplets; sterigmata 4.8- 8.3 × 1.4-2.2 µm.
Lamellar trama
Composed of nested sphaerocytes measuring 18.5-55.5 × 17-43 µm and surrounded by connective hyphae.
Pleurocystidia
(35.5-) 38-62-83 (-91) × (4.5-) 6-7.5-10 µm, protruding up to 30 µm, narrowly clavate to narrowly cylindrical with obtuse or mucronate apices, thin-walled, with refractive contents, unchanging in SV.
Cheilocystidia
(34-)39-43-47(-51) × 4.5-5-6.5 µm, resembling pleurocystidia in shape but smaller in size, thin-walled, with refractive contents, unchanging in SV.
Marginal cells
Not differentiated.
Pileipellis
Composed of ascending to erect hyphae, orthochromatic in cresyl blue; hyphae 2-6 µm in width, cylindrical, septate, some with incrustation and brown dispersive pigments; terminal cells (8-)11-23-36(-38.5) × 2.5-4-6(-7.5) µm, usually cylindrical with obtuse apices and brown pigments, lageniform, clavate to cylindrical, some with short rostrate apicesor granular contents.
Pileocystidia
None found.
Stipitipellis
Composed of erect hyphae, 40-90 µm wide; hyphae 1.5-4 µm in width, narrowly cylindrical, septate; terminal cells (6.5-)13- 22-31(-39) × 2-4-6(-7.5) µm, thin-walled, usually hyaline, cylindrical to clavate with obtuse apices.
Caulocystidia
None found.
Clamp connections
Absent.
NOTES
Russula latolamellata Y.Song & L.H.Qiu, sp. nov., morphologically resembles R. schaefferina Rawla & Sarwal, including pileus color and features of pileipellis, size and ornamentations of basidiospores and absence of both pileocystidia and caulocystidia, etc. However, it differs substantially from our species in its finely pruinose pileus with uncracking surface, thin and crowded lamellae, and further also by shape and size of pleurocystidia (85-98 × 10-14 µm), and cheilocystidia (35-50 × 9-13 µm), and the hollow stipe covered with ochraceous or brown depressed fibrillose scales (Rawla & Sarwal 1983). When bruised, context of R. latolamellata Y.Song & L.H.Qiu, sp. nov., directly becomes reddish brown without turning black first.
Although all three specimens of R. latolamellata Y.Song & L.H.Qiu, sp. nov., were collected from the broadleaf forest of DHSBR, several ITS sequences that have a sequence similarity of about 99% to that of R. latolamellata Y.Song & L.H.Qiu, sp. nov., retrieved from soil in the pine and broadleaf mixed forest of DHSBR are available in GenBank, implying that the species may be common in DHSBR.
Russula nigrocarpa S.Y.Zhou,Y.Song & L.H.Qiu, sp. nov.
(Figs 5; 6)
MYCOBANK NUMBER. — MB 835727.
HOLOTYPE. — China. Guangdong Province, Zhaoqing City, Dinghushan Biosphere Reserve, on the ground in broadleaf forest, 16.VII.2019, S. Y. Zhou K19071603 (GDGM 79720).
ETYMOLOGY. — Named after its dark black pileus.
DIAGNOSIS. — Mainly characterized by its dry, cracking, dark brown to dark black pileus, off-white lamellae, basidiospores with complete reticulate ornamentations, hymenial cystidia and pileocystidia of various forms with often forked apices, strongly glutinous pileipellis composed of hyphae usually with dark brown vacuolar pigments.
HABITAT AND DISTRIBUTION. — Solitary or gregarious in evergreen broadleaf forest.
ADDITIONAL SPECIMENS EXAMINED. — China. Guangdong Province, Zhaoqing City, Dinghushan Biosphere Reserve, on the ground in broadleaf forest, 5.V.2018, J. W. Li, Y. Song K18050529 (GDGM 79721).
DESCRIPTION
Basidiomata
Medium to large sized, agaricoid.
Pileus
6-10cm in diameter,applanate to concave when mature;surface dry, dark brown to dark black; margin entire, turning slightly upward.
Lamellae
Adnate to slightly decurrent, sparse, 6 pieces of lamellae and lamellulae/cm at the margin of pileus, broad, unequal; surface off-white to cream or yellowish, becoming dark brown when bruised; gill edge concolorous, becoming dark brown to black when old (probably from drying out).
Stipe
3-5 × 2.5-4 cm, central, cylindrical, sometimes tapering downwards, solid, off-white, becoming grayish white when mature, turning dark brown when bruised.
Context
White, becoming directly black when bruised without reddening first, 6-8 mm thick near stipe.
Odour
Unpleasant.
Taste
Not taken.
Spore print
White to cream.
Basidiospores
Subglobose to ellipsoid, [40/2/2] 4.3-4.8-5.4 (-5.8) × (3.4-) 3.7- 4-4.4 (-4.6) µm, Q = 1.10-1.19-1.28 (-1.35); ornamentations amyloid, composed of low ridges forming a complete reticulum; suprahilar spot inamyloid.
Basidia
(22-) 26.5-31-35 (-46.5) × 5-6.5-8µm, clavate to cylindrical, 1-, 2-, 3- or 4-spored, with refractive contents; sterigmata 1.8-6 µm long.
Lamellar trama
Composed of nested sphaerocytes surrounded by connective hyphae.
Pleurocystidia
(31-) 35-41-52 (-58) × 3.5-5-6.5 µm, of various forms, narrowly cylindrical to slightly flexuose with obtuse, mucronate, moniliform, inflorescence-like or forked apices, thin-walled, with refractive contents, unchanging in SV.
Cheilocystidia
25-29-35 × 3-4-5 µm, narrowly cylindrical to slightly flexuous with obtuse or rostrate apices, with refractive contents, thin-walled, unchanging in SV.
Marginal cells
Not differentiated.
Pileipellis
Composed of ascending to erect hyphae, strongly gelatinized, 150-220 µm thick, orthochromatic in cresyl blue; hyphae 2-6 µm wide, narrowly cylindrical, septate, often with dark brown pigments; terminal cells 12.5-17-22 (-25) × 2.5-4-6 (-7) µm, cylindrical to narrowly clavate with obtuse or slightly acute apices, some with dark brown pigments.
Pileocystidia
16.5-25-33.5 × 2.5-4-5.5 µm, subclavate to cylindrical, apices mucronate to inflorescence-like, with refractive contents, thin-walled, unchanging in SV.
Stipitipellis
Composed of ascending to erect hyphae, 60-100 µm thick, gelatinous; hyphae 1.5-4 µm wide, narrowly cylindrical, septate; terminal cells (8-) 10-19-31 (-34) × 2.5-5-9 (-10) µm, cylindrical to narrowly clavate with obtuse apices, sometimes containing brown pigments.
Caulocystidia
(16.5-) 21-34-52 (-56) × 3.5-4.5-6 µm, thin-walled, cylindrical with obtuse or short rostrate apices.
Clamp connections
Absent.
NOTES
R. nigrocarpa S.Y.Zhou, Y.Song & L.H.Qiu, sp. nov., is closely related to R. acrifolia in our multilocus phylogeny (Figs 1; 2). The latter species differs from R. nigrocarpa S.Y.Zhou, Y.Song & L.H.Qiu, sp. nov., in its viscid, grayish brown pileus, context that turns red then gray to black when bruised, much crowded lamellae and grayish brown stipe but, above all, in the much larger size (6.0-9.5 × 5.5-7.5 µm) of its basidiospores (Çolak & Işiloğlu 2016). The exceptionally small size of the spores of R. nigrocarpa S.Y.Zhou, Y.Song& L.H.Qiu, sp. nov., comparable to those of species in subg. Archaeae, was hitherto undocumented within subg. Compactae, making it impossible to confuse our species with any of the other Asian or northern hemisphere species in the same subgenus.
description: Published as part of Zhou, Songyan, Song, Yu, Chen, Kaixing, Li, Jingwei, Buyck, Bart & Qiu, Lihong, 2020, Three novel species of Russula Pers. subg. Compactae (Fr.) Bon from Dinghushan Biosphere Reserve in southern China, pp. 219-234 in Cryptogamie, Mycologie 20 (14) on pages 222-232, DOI: 10.5252/cryptogamie-mycologie2020v41a14, http://zenodo.org/record/7814990