3.2. Taxonomy
Mycobank—MB861771.
Etymology—refers to the short ridge ornamentation of spores.
Holotype—CHINA. Shanxi Province: Jincheng City, Qinshui County, Lishan Mountains, Zhongcun Forest Farm, 1651 m, 22 August 2019, on the ground in the mix-forest dominated by Quercus wutaishansea and Pinus tabuliformis, collected by C. Yang YCM031 (BJTC FM715).
Description—Basidiocarps medium to large-sized. Pileus 4.2–12 cm in diam, at first flat hemispheric to hemispheric, then expanding to flat, applanate, often depressed at center; moderately to strongly tuberculate-striate up to 1/3 to 1/2 pileus radius when mature; surface dull, viscid when wet, pale yellow (#fff3b6), yellow brown (#eac200) or straw yellow (#9e8300). Lamellae adnate, lamellulae absent or rare, furcation absent, white (#ffffeb), turning pale yellow (#ffd784) when bruised, edge entire, concolorous. Stipe 7–12 × 2.3–4 cm, hollow, with internally bamboo-like septate cavities, nearly equal in thickness, slightly tapered at the base, white (#ffffeb) to cream (#ffd784), surface with longitudinal rugulose with age, turning pale brown (#ffc652) when bruised. Context 0.3–0.4 cm thick at pileus center, white (#ffffeb). Odor not distinctive. Taste not distinctive. Spore print cream color.
Basidiospores [60/4/2] 7.2–9.6(10.2) × (6.8)7.1–9.3(9.8) μm (Q = 1.04–1.2, Qm = 1.12 ± 0.08), subglobose to globose, ornamentation short ridged or rarely subreticulate, 0.7–1.6 (1.9) μm high, amyloid; hilar appendix 1.3–2.5 μm, amyloid. Basidia (34.8)38–50.9(54.6) × 10.9–14.9 μm, clavate, 2–4-spored, sterigmata 3.3–7.9 μm long, hyaline in 5% KOH. Pleurocystidia 51.1–62.9(67.3) × 8–11.7(12.7) μm, cylindrical-fusiform, apex occasionally minutely papillate or elongate, contents granular, brownish yellow in sulphovanillin. Cheilocystidia 40–61.8 × 6.9–12.7 μm, clavate-fusiform to cylindrical, apex papillate, contents granular. Lamellar trama irregular. Subhymenium 19.1–23.7 μm thick, composed of sphaerocytes and hyphae. Pileipellis metachromatic in Cresyl blue, two-layered, superpellis an ixocutis, 100.9–126.1 μm thick, composed of hyphae, terminal cells 9.8–13.8 × 3–3.9 μm, cylindrical-clavate with occasional subglobose apical swellings (4–5 μm diam); subpellis an ixocutis, 190.5–235 μm thick, pigmentation reduced. Pileocystidia 15.7–33.7 × 2.6–6.6 μm, flask-shaped, apex aculeate, basal cells inflated, containing granular inclusions. Terminal cells of stipitipellis, clavate. Caulocystidia (33)35.2–40.5(44.8) × 3.3–6.6 μm, clavate, flask-shaped, containing granular inclusions. Clamp connections absent.
Habitat and distribution—Solitary on the ground in a mixed coniferous and broad-leaved forest dominated by Quercus wutaishansea and Pinus tabuliformis.
Additional specimens examined—CHINA. Shanxi Province: Jincheng City, Qinshui County, Tuwo Town, Shangwoquan Village, on the ground in the mix-forest dominated by Quercus wutaishansea and Pinus tabuliformis, 1150 m, 26 July 2021, collected by N. Mao, J.C. Lv, Li F and J.Z. Cao MNM342 (BJTC FM1783).
Comments: Russula brevicostata is characterized by its lamellae that is nearly completely absent of both furcation and lamellulae, hollow stipes with internally bamboo-like septate cavities, and spores ornamented with short ridges.
Phylogenetically,
R. brevicostata is classified in the subgen.
Heterophyllidia (
Figure 3 and
Figure 4).
Russula quercicola from Pakistan sisters to
R. brevicostata, but it can be differentiated by its spores with nearly complete reticulate ornaments.
Russula fluvialis (
Figure 3) and
R. parafluvialis (
Figure 3 and
Figure 4), another new species described in this paper, are also related and highly similar to the present species. Of them,
R. fluvialis is distinguished from
R. brevicostata by its conifer habitat and different phylogenetic position [
50,
51];
R. parafluvialis by its frequent furcations of lamellae and spores ornamented with isolated warts (this paper).
Mycobank—MB861772.
Etymology—refers to the partial cracking of pileal surface.
Holotype—CHINA. Shanxi Province: Jincheng City, Qinshui County, Li Mountains, Zhongcun Forest Farm, 1680 m, 24 August 2020, on the ground in the mix-forest dominated by Quercus sp. and Pinus sp., collected by J.Z. Cao LH1146 (BJTC FM1006).
Description—Basidiocarps small-sized. Pileus 3.4–5 cm in diam, flat-hemispheric to applanate, slightly depressed with a recurved margin, partly cracked when mature, surface dry, slightly viscid when wet, dark green (#05af70), gradually transitioning to dull yellowish-green (#7fc806) at the disc, margin whitish-green at maturity. Lamellae adnate, dense, lamellulae and furcations absent, white (#ffffeb), aging to cream color (#ffdd35). Stipe 4–4.2 × 1–1.2 cm, hollow, cylindrical, tapering basally, cream-colored (#ffdd35), surface longitudinally rugulose with age. Context 0.3–1 mm thick, yellowish-white (#ffd784). Odor not distinctive. Taste not distinctive. Spore print cream color.
Basidiospores [60/2/1] (5.2)5.7–6.7(7.3) × (4.3)5.0–5.7(5.7) µm, Q = (1.04)1.09–1.29(1.3), Qm = 1.19 ± 0.1, subglobose to broadly ellipsoid, ornamentation of isolated fine warts, 0.7–1.1 µm high, amyloid; hilar appendix 0.7–1.1 µm long, amyloid. Basidia 31.1–39.8 × 8.3–11.9 µm, clavate, 2–4-spored, hyaline to pale yellow in 5% KOH. Lamellar trama dominated by sphaerocytes. Subhymenium 30.7–47.8 μm thick, composed of sphaerocytes and hyphae. Pleurocystidia (51.5)52.5–66.7(68.5) × 9.3–13.2(15.5) µm, fusiform to flask-shaped, occasionally with apical protrusions, containing refractive inclusions, negative to sulphovanillin. Cheilocystidia (47.2)49.1–60.4(62.6) × (7.6)8.6–11.5 µm, morphologically similar to pleurocystidia but smaller. Pileipellis a loosely interwoven ixocutis, metachromatic in Cresyl blue; hyphae 3–4 µm wide, slightly thick-walled, yellow-pigmented; terminal cells (9.6)11.3–15.5 × 2.6–3.7 µm, cylindrical, sometimes partly inflated, up to 5 µm wide, apically obtuse. Pileocystidia (27.6)32.7–33.5(37.9) × 5.4–7.1 µm, containing granular inclusions. Terminal cells of stipitipellis, clavate. Caulocystidia (32.8)35.2–40.9(42.8) × 5.7–8.0(8.3) µm, clavate, containing granular matter. Clamp connections absent.
Habitat—Solitary or scattered on the ground in mixed forests dominated by Quercus wutaishansea and Pinus sp.
Comments: Russula demirimosa is characterized by relatively small basidiocarps, gray-green and partly cracked pileus, spores ornamented with isolated fine warts and fusiform to flask-shaped cheilocystidia.
Phylogenetically,
R. demirimosa is classified in the subgen.
Heterophyllidia (
Figure 3 and
Figure 4) and sisters to
R. swatica from Pakistan (
Figure 3), but
R. swatica can be differed by its gray green pileus lacking cracks [
52]. There are five other species related to the present species, including
R. atroglauca, R. faustiana, R. galochroa, R. subterfurcata, and
R. shawarensis (
Figure 3). However,
R. atroglauca and
R. shawarensis have no cracks on pileus surface;
R. faustiana exhibits a pale ochraceous pileus with rust-brown maculae or striations, and spore ornamentation featuring cristate ridges and zebroid patterns;
R. subterfurcata and
R. galochroa possess white pileus, more or less with ocher, lilac, gray-olive shades, and furcated lamellae (abundant in
R. subterfurcata, sporadic in
R. galochroa) [
53,
54,
55,
56,
57]. All of which distinguish these five species from the present species.
Mycobank—MB861773.
Etymology—dongya, Chinese, means East Asia, refers to the region where the species is distributed.
Holotype—CHINA. Shanxi Province: Jincheng City, Qinshui County, Li Mountains, Zhongcun Forest Farm, 1640 m, 25 July 2021, on the ground in the forest dominated by Quercus wutaishansea, collected by N. Mao, J.C. Lv, Li F and J.Z. Cao MNM355 (BJTC FM1753).
Description—Basidiocarps small to medium-sized. Pileus 3.5–6 cm diam, at first flat-hemispheric with incurved margin, then expanding to flat, applanate, often depressed at the center when mature; tuberculate-striate up to 1/3 pileus radius, surface slightly viscid when wet, pale yellow (#fff0d2) at first, tinged with pale brown (#ffd456), yellowish brown (#d49f00) to straw color when mature, generally darker at center, Lamellae adnate, white (#ffffeb), furcations present, especially near the stipe, lamellulae absent or rare. Stipe 5.9–7 × 1.7–2.3 cm, hollow, subequal in thickness, occasionally slightly swollen medially, white (#ffffeb), surface longitudinally striated, slightly turning pale brown (#ffe18a) when bruised. Context 0.14–0.3 cm thick at pileus center, white (#ffffeb). Odor not distinctive. Taste not distinctive. Spore print white.
Basidiospores [90/10/2] (5.9)6.2–7.8 × (5.2)6.3–5.9(6.4) μm (Q = 1.01–1.5, Qm = 1.25 ± 0.25), globose to ellipsoid, ornamentation shortly cylindrical, apex obtuse or truncate, 0.5–1 μm high, occasionally fused into short ridges or larger warts, amyloid; hilar region with reduced ornamentation; hilar appendix 1–2.4 μm, weakly amyloid. Basidia (30.2)35.7–46.4(51.6) × 10–11.4(12.4) μm, clavate, 2–4-spored, sterigmata 3.1–7.5 μm long, hyaline in 5% KOH. Pleurocystidia (40.7)43.1–55.5(58.4) × 8.1–11.5(13.1) μm, fusiform to elongate-clavate, containing granular inclusions, slightly brownish yellow in sulphovanillin. Cheilocystidia 46.2–67.3(69.5) × 8–12.4 μm, clavate-ventricose, with apical prolongations up to 4 μm in length, containing granular inclusions. Lamellar trama irregular. Subhymenium 19–32.9 μm thick, composed of sphaerocytes and hyphae. Pileipellis metachromatic in Cresyl blue, two-layered, suprapellis ixocutis, 24.4–53.7 μm thick, composed of hyphae (2–4.4 μm wide), hyaline in 5% KOH, terminal cells 5.1–15.9(17.8) × 2.2–4.6 μm, clavate to ventricose, hyaline; subpellis cutis, 60.6–79.9 μm thick. Pileocystidia (14.7)16.5–39.3(42.5) × 3.2–5.9 μm, fusiform to ventricose, containing granular inclusions. Terminal cells of stipitipellis subclavate to clavate. Caulocystidia (24.4)28.2–38.9 × 3.4–6.5 μm, fusiform to lageniform, containing granular inclusions. Clamp connections absent.
Habitat and distribution—Solitary or scattered on the ground in a broad-leaved forest dominated by Quercus wutaishansea.
Additional specimens examined—CHINA. Shanxi Province: Changzhi City, Qinyuan County, Lingkong Mountains, Shengshou Temple, 1510 m, 24 July 2021, on the ground in the mix-forest dominated by Quercus sp. and Pinus sp., collected by N. Mao, J.C. Lv, Li F and J.Z. Cao LJC008 (BJTC FM1718).
Comments:
Russula dongyaensis is characterized by its straw-colored pileus, basidiospores ornamented with short cylindrical warts with obtuse or truncate apex, and generally clavate to ventricose cystidia. Phylogenetically,
R. dongyaensis is classified in the subgen.
Heterophyllidia (
Figure 3 and
Figure 4) and closely related to
R. amerorecondita from North America and
R. recondita (
Figure 3) from Europe.
Russula amerorecondita is differed from
R. dongyaensis by its orange, yellow-orange pileus and larger spores of (8–)8.5–9.6–10.7(–11.84) 9 (6.2–)7.4–8.5–9.5(–10.6) µm [
1];
R. recondite by its ochraceous, fawn, ochre honey, ochre-gray-bistre pileus with almost always darker at the center, the absence of lamellae furcation, and spores ornamented with mainly isolated spines or warts [
58]. Moreover, the North American
R. pectinatoides is morphologically similar to
R. dongyaensis as it also has small spores, but it is distinguished by its spore ornaments that are almost completely isolated warts.
Mycobank—MB861774.
Etymology—refers to honoring Prof. Bo Liu, a Chinese mycologist.
Holotype—CHINA. Shanxi Province: Jincheng City, Lingchuan County, Duohuo Town, on the ground in the forest dominated by Quercus sp., 1182 m, 8 August 2023, collected by H.Y. Fu, H.M. Ji and Y. Li MS495 (BJTC FM3439).
Description—Basidiocarps medium-sized. Pileus 5.2–8.6 cm diam, convex to applanate, slightly depressed at the center, margin very shortly striated, surface viscid to dry, red (#ff4000), peach-red (#ff6b00) to scarlet (#ff974d), often spotted with yellow (#ffdd35) patches. Lamellae adnate, dense, lamellulae frequently present, furcations present, white (#ffffeb) at first, creamy (#ffee9c) to off yellowish (#ffe7b6) at maturity, edge entire, concolorous. Stipe 7.1–8.9 × 1.8–2.1 cm, hollow, subequal, slightly tapered at the base, white (#ffffeb) to whitish, turning yellowish to pale brown (#ffffb8) when bruised. Context 0.3–0.4 cm thick at pileus center, white-cream (#ffffeb). Odor indistinct. Taste slightly saline. Spore print cream color.
Basidiospores [90/16/8] 7–8.9 × 6.7–7.8(8.2) μm (Q = 1.01–1.22, Qm = 1.11 ± 0.11), subglobose to broadly ellipsoid, ornamentation verrucouse and shortly ridged, 0.3–0.9 μm high, occasionally interconnected into partly discontinuous reticulum, amyloid; hilar appendix (0.6)0.7–1.6(1.7) μm, amyloid. Basidia (34.2)36.4–46.3(62) × 10.3–13.6 μm, clavate, 2–4-spored, sterigmata 2.5–9.8 μm long, hyaline in 5% KOH. Pleurocystidia 55.9–81.1(87) × 11.5–14(15.4) μm, clavate, apex occasionally elongated (≤7.4 μm), containing granular inclusions, brownish yellow in sulphovanillin. Cheilocystidia (38.3)42.4–63.7(66.7) × 7.6–14.6 μm, clavate to ventricose, containing granular inclusions. Lamellar trama divergent, Subhymenium 31.4–34.6 μm thick, composed of sphaerocytes and hyphae. Pileipellis metachromatic in Cresyl blue, two-layered: suprapellis trichoderm, 41.8–84.4 μm thick, terminal cells 8.5–21.7 × 2.2–4 μm, hyaline, clavate-ventricose; subpellis 88.1–184.7 μm thick, composed of interwoven hyphae. Pileocystidia (40.5)49.1–70.1(79.7) × (5)6.5–8.5(9.5) μm, clavate to ventricose, containing granular inclusions. Terminal cells of stipitipellis subclavate to clavate. Caulocystidia (38.1)53.7–64.3(76.4) × (3.5)5.7–6.9(8.6) μm, clavate to ventricose, containing granular inclusions. Clamp connections absent.
Habitat—Solitary or scattered on the ground in broad-leaved forests dominated by Quercus sp.
Additional specimens examined—CHINA. Shanxi Province: Linfen City, Jiexiu County, Mian Mountains, on the ground in the forest dominated by Quercus sp. 1538 m, 7 August 2023, collected by H.Y. Fu, H.M. Ji and Y. Li MS021 (BJTC FM2969), MS025 (BJTC FM2973); ibid, 1393 m, 8 August 2023, collected by H.Y. Fu, H.M. Ji and Y. Li MS085 (BJTC FM3032); ibid, Jincheng City, Qinshui County, Li Mountains, Zhongcun Forest Farm, 1642 m, 10 August 2022, collected by N. Mao, J.C. Lv, Li F and J.Z. Cao MNM585 (BJTC FM2255); ibid, Xiachuan Town, 1821 m, collected by H.Y. Fu, H.M. Ji and Y. Li MS378 (BJTC FM3323); ibid, Lingchuan County, Duohuo Town, 1157 m, 28 August 2023, collected by H.Y. Fu, H.M. Ji and Y. Li MS502 (BJTC FM3446); ibid, 1680 m, 24 August 2020, collected by J.Z. Cao LH1120 (BJTC FM982).
Comments: Russula liuboanum is characterized by its red pileus usually spotted with irregular yellow patches, white stipe lacking red flush, and spores ornamented with isolated warts and ridges.
Phylogenetically,
Russula liuboanum is classified in the subgen.
Russula (
Figure 5 and
Figure 6). could be related to the North American
R. pusilla and the European
R. laeta,
R. integriformis,
R. velenovskyi, and
R. veternosa (
Figure 5). However,
R. pusilla is morphologically distinguished from
R. liuboanum by its small basidiomata, light red pileus that is even and absent of yellow spot or patch, and spores ornamentation almost completely reticulated [
50,
59];
R. laeta by its bright yellow to pale ochraceous-yellow pileus, stipe without discoloration when bruised, pale yellow to pale ochraceous spore print, and the absence of caulocystidia [
60];
R. integriformis by its context turning pale yellow to ochraceous yellow when bruised, pale yellow to yellow spore print, and the absence of caulocystidia [
60].
R. velenovskyi by its coral red to violet brown pileus lacking spotted yellow patches [
61];
R. veternosa by its pileus margin with faintly striatations, the absence of lamellulae, stipe no bruising discoloration, pale yellow to pale ochraceous spore print, and the absence of caulocystidia [
56].
Mycobank—MB861775.
Etymology—refers to the similarity to Russula fluvialis.
Holotype—CHINA. Shanxi Province: Linfen City, Yicheng County, Shihe Forestry Station, Songshugou, 1907 m, 20 August 2019, on the ground in the mix-forest dominated by Betula platyphylla, Quercus liaotungensis and Pinus tabulaeformis, collected by C. Yang YCM003 (BJTC FM627).
Description—Basidiocarps small to medium-sized. Pileus 2–8 cm diam, flat-hemispheric, hemispherical at first, then flat or convex with a depressed center, moderately to strongly tuberculate-striate up to 2/3 or more of pileus radius when mature, surface viscid to dry, smooth, ochre, beige, light yellow (#e1c606) or straw yellow (#e19006). Lamellae adnate, dense, lamellulae present, furcations numerous, white (#ffffeb) to cream (#ffdd35), edge entire, concolorous. Stipe 3–12 × 1–2 cm, cylindrical to subcylindrical, slightly tapered or broadly rounded at the base, hollow, white (#ffffeb), smooth, longitudinally rugulose with age, turning pale brown (#fce485) to brown (#faa43b) when bruised. Context 2–4 mm thick at pileus center, white (#ffffeb) to yellowish-white (#ffdd35). Odor not distinctive. Taste not distinctive. Spore print cream color.
Basidiospores [100/14/7] 7.2–9.3(9.8) × (6.8)7.1–9.6(10.2) μm (Q = 1.01–1.20, Qm = 1.1 ± 0.1), subglobose, occasionally globose, ornamentation of isolated warts, 0.7–1.9 μm high, sparse (2–3 in a 3 μm diam. circle), occasionally connected by low line, amyloid; hilar appendix 1.3–2.5 μm, amyloid. Basidia (34.8)38–50.9(54.6) × 10.9–14.9 μm, clavate, 2–4-spored, sterigmata 3.3–7.9 μm long, hyaline in 5% KOH. Pleurocystidia 51.1–62.9(67.3) × 8–11.7(12.7) μm, cylindrical to subfusiform, apex obtuse, sometimes minutely or slightly long papillate, contents granular, negative to sulphovanillin. Cheilocystidia 40–61.8 × 6.9–12.7 μm, clavate to fusiform, sometimes cylindrical, apex papillate, contents granular. Lamellar trama bilateral, composed of interwoven hyphae. Subhymenium 47.3–60.3 μm thick, composed of sphaerocytes and hyphae. Pileipellis not metachromatic in Cresyl blue, two-layered, suprapellis an ixocutis, 53.6–60.3 μm thick, terminal cells (9.2)12.1–16.3 × 2.6–3.2 μm, cylindrical to fusiform, cylindrical or mammillate, occasionally inflated into a globose shape; subpellis an ixocutis, 58.3–66.5 μm thick. Pileocystidia (17.9)19.2–32.8(39.9) × 3–5.9(7.3) μm, subclavate, subfusiform to flask-shaped, with oily granular contents. Terminal cells of stipitipellis clavate. Caulocystidia 30.4–42.5(47.2) × 4.6–6.8(7.4) μm, subfusiform, flask-shaped, or clavate, contents granular. Clamp connections absent.
Habitat and distribution—Scattered or in groups in forest of Betula platyphylla or in mixed forests of B. platyphylla, Quercus liaotungensis and Pinus tabulaeformis.
Additional specimens examined—CHINA. Shanxi Province: Linfen City, Huozhou County, Qiliyu Town, 1830 m, 29 July 2021, on the ground in the mix-forest dominated by B. platyphylla, Quercus liaotungensis and Pinus tabulaeformis, collected by N. Mao, J.C. Lv, Li F and J.Z. Cao LJC099 (BJTC FM1910); ibid, Lvliang City, Jiaocheng Country, Pangquangou National Nature Reserve, on the ground in the mix-forest dominated by Quercus sp. and Pinus sp., 1883 m, 18 August 2023, collected by H.Y. Fu, H.M. Ji and Y. Li MS342 (BJTC FM3287); ibid, Jincheng City, Qinshui County, Xiachuan Town, 1782 m, 28 August 2023, collected by H.Y. Fu and H.M. Ji MS387 (BJTC FM3332).
Comments:
Russula parafluvialis is characterized by its yellowish pileus with long margin tuberculate-striate, lamellae with numerous furcation and spores with isolated warts. Phylogenetically,
R. parafluvialis is classified in the subgen.
Heterophyllidia (
Figure 3 and
Figure 4).
Russula fluvialis is closely related to our new species (
Figure 3); however,
R. fluvialis is a boreal species occurring in
Picea spp.-dominated forest, and morphologically it can be differentiated by its pileus with short margin tuberculate-striate up to 1/3 of the radius, the less frequent furcations of lamellae and the smaller spores (7.1–)7.4–7.7–8.1(–8.7) × (6.1–)6.3–6.6–6.9(–7.4) μm with partly connected warts [
1].
Russula brevicostata and
R. dongyaensis, the other two new species described in this paper, are also related and highly similar to the present species. Of them,
R. brevicostata can be differentiated by its different plant host (absolutely associated with
Quercus spp.), and the ornaments of spores, which is typically short ridges rather than isolated warts;
R. dongyaensis by its clearly smaller spores of (5.9)6.2–7.8 × (5.2)6.3–5.9(6.4) μm (this paper).
Mycobank—MB861805.
Etymology—refers to the type locality of the new species.
Holotype—CHINA. Shanxi Province: Linfen City, Pu County, Wulu Mountains, on the ground in the forest dominated by Quercus sp. 1510 m, 28 July 2021, collected by N. Mao, J.C. Lv, Li F and J.Z. Cao MNM267 (BJTC FM1868).
Description—Basidiocarps medium-sized. Pileus 4.1–8.5 cm diam, flat-hemispheric to hemispherical at first, then expanding to convex or plano-convex with a depressed center, surface dry, smooth, uneven or spotted, yellow brown (#d1a54a), gray brown (#e6d49b), dark gray brown (#d7ba5e) to dark brown (#a53f2a), margin sometimes tuberculate striated when old and dry. Lamellae adnate, dense, lamellulae absent or rare, furcations absent or rare, white (#ffffeb) to cream (#ffdd35), edge entire, concolorous, turning brown (#d28d00) when bruised. Stipe 3.5–9 × 1.1–2 cm, cylindrical to subcylindrical, solid, white (#ffffeb), smooth, longitudinally rugulose with age, turning pale brown (#e6d49b) to brown (#d7ba5e) when bruised. Context 0.1–0.3 cm thick, white (#ffffeb). Odor not distinctive. Taste not distinctive. Spore print yellow.
Basidiospores [80/12/6] (7.3)7.8–10.1(10.9) × (6.4)6.9–9.1(9.6) μm (Q = 1.01–1.3, Qm = 1.15 ± 0.15), globose to broadly ellipsoid, ornamentation echinate, 0.4–0.8 μm high, amyloid; hilar appendix (0.6)0.8–1.5(1.8) μm, amyloid. Basidia (29.1)31.9–40.8(43.6) × (10.3)11.7–15.1(16.1) μm, ventricose, 2–4-spored, sterigmata 3.6–7.6 μm long, hyaline in 5% KOH. Pleurocystidia (49.8)53.2–76.4 × 10.5–13.5 μm, cylindrical to clavate, apically extended with hyaline protrusions (up to 13.9 μm long), containing granular inclusions, nrgative to sulo-vanillin. Cheilocystidia (58.5)61.9–73.9(79.4) × (8.8)9.6–12.1 μm, cylindrical to ventricose, containing granular inclusions. Lamellar trama irregular, composed of interwoven hyphae and abundant inflated cells of (30.7)40–51.6 × (25.8)27.2–38.8 μm. Subhymenium 51–71.8 μm thick, composed of sphaerocytes and hyphae. Pileipellis metachromatic in Cresyl blue, two-layered without distinct stratification: suprapellis trichoderm, 53.9–88.1 μm thick, terminal cells 11.2–20.1 × 2.2–4.4 μm, hyaline, fusiform to lageniform; subpellis Interwoven, 97.1–122 μm thick. Pileocystidia (36)36.3–73.1(75.3) × 4.5–8.2 μm, fusiform, containing granular inclusions. Terminal cells of stipitipellis subclavate to clavate. Caulocystidia (33.2)36.8–58.9(65.5) × 5.6–9.9(11) μm, cylindrical to clavate, containing granular inclusions. Clamp connections absent.
Habitat—Solitary on the ground in a broad-leaved forest dominated by Quercus sp.
Additional specimens examined—CHINA. Shanxi Province: Linfen City, Pu County, Wulu Mountains, on the ground in the forest dominated by Quercus sp. 1510 m, 28 July 2021, collected by N. Mao, J.C. Lv, Li F and J.Z. Cao MNM391 (BJTC FM1899); ibid, alt. 1540 m, 14 August 2022, collected by N. Mao, J.C. Lv, Li F and J.Z. Cao LJC276 (BJTC FM2399); ibid, Linfen City, Jiexiu County, Mian Mountains, 1398 m, 8 August 2023, collected by H.Y. Fu, H.M. Ji and Y. Li. MS086 (BJTC FM3038), MS091 (BJTC FM3038); ibid, Jincheng City, Qinshui County, Li Mountains, Zhongcun Forest Farm, 1642 m, 22 August 2019, collected by C. Yang YCM025 (BJTC FM709).
Comments: Russula puxianensis is characterized by its uneven pileus of various shades of brown and gray, but without any red tints, white stipe and spores ornamented with isolated echinates.
Phylogenetically,
Russula puxianensis is classified in the subgen.
Russula (
Figure 5 and
Figure 6) and sisters to
R. heilongjiangensis (
Figure 5), a species described from northeastern China [
9]. Morphologically,
Russula heilongjiangensis possesses a carmine-red pileus and lamellae edge without cheilocystidia, by which it differs from
R. puxianensis. The European
R. globispora is sometimes morphologically similar to
R. puxianensis by its brown pileus with shades of various color; however, the pileus in
R. globispora has distinct red tints, by which it differs from
R. puxianensis clearly [
62].
Mycobank—MB861806.
Etymology—refers to its close relationship to Russula olivacea but with red color of cap.
Holotype—CHINA. Shanxi Province: Jincheng City, Qinshui County, Tuwo Town, Shangwoquan Village, on the ground in the forest dominated by Quercus sp., 1090 m, 26 July 2021, collected by N. Mao, J.C. Lv, Li F and J.Z. Cao LJC052 (BJTC FM1821).
Description—Basidiocarps large-sized. Pileus 7.9–10.2 cm diam, hemispherical to applanate, surface dry and usually granulate, red (#b60000), scarlet to dark red (#9d0000). Lamellae adnate, lamellulae and furcations present, white (#ffffeb) at first, cream-colored (#ffdd35) to pale yellowish (#ffd784) at maturity, edge entire, concolorous. Stipe 8.5–10 × 2–4 cm, cylindrical, solid, white (#ffffeb), sometimes flushed pink (#ffc5c0), surface with longitudinal rugulose with age. Context 0.5–0.8 cm thick, white. Odor not distinctive. Taste slightly burning. Spore print cream color.
Basidiospores [60/4/3] 8.2–9.5 × 7.7–8.9 μm (Q = 1.02–1.15, Qm = 1.08 ± 0.06), globose to subglobose, ornamentation echinate, 0.4–0.8 μm high, usually interconnected into short ridges or sub-reticulate pattern, amyloid; hilar appendix (0.6)1–1.6 μm, amyloid. Basidia 48.9–63.4(68.3) × 12.7–14.7 μm, clavate, 2–4-spored, sterigmata 4.4–9.2 μm long, hyaline in 5% KOH. Pleurocystidia (90.8)93.1–119.8(121.1) × 10–15.8 μm, ventricose, apically extended with hyaline protrusions (up to 10.3 μm long), containing granular inclusions, negative to sulphovanillin. Cheilocystidia (84.6)89.5–108.5(112.1) × (12.6)13.9–15.2(16.7) μm, ventricose, apically extended with hyaline protrusions (up to 5.5 μm long), containing granular inclusions. Lamellar trama irregular, composed of interwoven hyphae. Subhymenium pseudoparenchymatous, 23.7–31.2 μm thick. Pileipellis metachromatic in Cresyl blue, two-layered: suprapellis trichoderm, 58.6–93.6 μm thick, hyaline in 5% KOH, terminal cells (10.2)12.1–22.8 × 3.7–5.6(6.6) μm, hyaline, clavate to ventricose; subpellis interwoven, 114.2–159.6 μm thick. Pileocystidia absent. Terminal cells of stipitipellis subclavate to clavate. Caulocystidia absent. Clamp connections absent.
Habitat—solitary or scattered on the ground in forests dominated by Quercus sp.
Additional specimens examined—CHINA. Shanxi Province: Jincheng City, Lingchuan County, Duohuo Town, on the ground in the forest dominated by Quercus sp., 1182 m, 27 August 2023, collected by H.Y. Fu, H.M. Ji and Y. Li MS470 (BJTC FM3415); ibid, Qinshui County, Tuwo Town, Shangwoquan Village, on the ground in the mix-forest dominated by Quercus sp. and Pinus sp., 1090 m, 26 July 2021, collected by N. Mao, J.C. Lv, Li F and J.Z. Cao LJC052-1 (BJTC FM1821-1).
Comments: Russula rubrolivacea is characterized by its red pileus surface with fine verrucose projections, white stipe sometimes with flushed pink, spores ornamented with echinate, which are usually interconnected into short ridges or sub-reticulate pattern, and the absence of pileocystidia. Moreover, the specific association with Quercus acutissima and Q. variabilis might also be unique for this new species.
Phylogenetically,
Russula rubrolivacea is classified in the subgen.
Russula (
Figure 5 and
Figure 6) and sisters to the European
R. olivacea (
Figure 1); however,
R. olivacea is differentiated from
R. rubrolivacea by its smooth olivaceous pileus and spores ornamented fine verrucae [
63].
Mycobank—MB861807.
Etymology—refers to the closely relationship with Russula curtipes in phylogeny.
Holotype—CHINA. Shanxi Province: Taiyuan City, Loufan Country, Yunding Mountains, on the ground in the forest dominated by Quercus sp., 1824 m, 23 August 2022, collected by J.C. Lv and N. Mao MNM730 (BJTC FM2493).
Description—Basidiocarps small to medium-sized. Pileus 3.7–6.8 cm diam, flat-hemispheric at first, then pulvinate to applanate; surface dry, yellow brown (#d1614a) when young, wine red (#ea686f) to pink-purple (#f0959a) at maturity, usually with a pale yellow (#ffdd35) center. Lamellae adnate, dense, lamellulae absent, furcation numerous, white (#ffffeb) to cream-colored (#ffdd35) at first, yellow (#ffd784) at maturity, edge entire, concolorous. Stipe 4–6.4 × 0.8–1.9 cm, hollow, slightly bulbous at the base, white (#ffffeb), smooth, surface with longitudinally rugulose with age. Context 0.2–0.4 cm thick at pileus center, white (#ffffeb) to cream (#ffdd35). Odor not distinctive. Taste faintly salty. Spore print yellow.
Basidiospores [60/4/2] 6.4–7.7(8.8) × 6–7.9 μm (Q = 1.01–1.16, Qm = 1.08 ± 0.08), subglobose to globose, ornamentation of isolated warts and discontinuous reticulate ridges, 0.4–0.7 μm high, amyloid; hilar appendix (0.7)0.9–1.2(1.5) μm, amyloid. Basidia 31.3–40.7(42.7) × (9.1)10.7–12.1(13.2) μm, clavate to ventricose, 2–4-spored, sterigmata 3.1–6.9 μm long, hyaline in 5% KOH. Pleurocystidia (38.1)40–60 × 7–10.8 μm, clavate to ventricose, containing granular inclusions, slightly gray in sulphovanillin. Cheilocystidia (32.1)35.4–57.8(69.6) × 6.1–10.7(13.3) μm, clavate, containing granular inclusions. Lamellar trama irregular, composed of hyphae and inflated cells of 8.1–15 μm diam. Subhymenium 25.9–30.2 μm thick, cellular. Pileipellis non-metachromatic in Cresyl blue, two-layered, suprapellis trichoderm, 66.6–84.5 μm thick, terminal cells 12.3–30.5 × 1.9–5.7(7.1) μm, hyaline, clavate to lageniform; subpellis 72.7–81.9 μm thick, composed of interwoven hyphae. Pileocystidia (33.2)36.3–55.2(65.2) × 4.5–8.6 μm, clavate, containing granular inclusions. Terminal cells of stipitipellis subclavate to clavate. Caulocystidia (31.2)34.1–51.1(54.7) × (3.4)5–8.1(9.1) μm, clavate, containing granular inclusions. Clamp connections absent.
Habitat—solitary on the ground in a broad-leaved forest dominated by Quercus sp.
Additional specimens examined—CHINA. Shanxi Province: Lvliang City, Jiaocheng Country, Pangquangou National Nature Reserve, on the ground in the mix-forest dominated by Quercus sp. and Picea asperata Mast., 2179 m, 18 August 2023, collected by H.Y. Fu, H.M. Ji and Y. Li MS346 (BJTC FM3291).
Comments: Russula sinocurtipes is characterized by its wine red to pink-purple pileus usually with a pale-yellow center area, lamellulae absent, basidiospores ornamented with warts and discontinuous reticulate ridges, clavate to ventricose cystidia.
Phylogenetically,
R. sinocurtipes is classified in the subgen.
Russula (
Figure 5 and
Figure 6) and closely related to the European
R. curtipes and
R. fontqueri (
Figure 1). Morphologically,
R. curtipes is differentiated from
R. sinocurtipes by its purple pileus, stout stem up to 1–4 cm in diam, and larger spores up to 7–9.5 × 6.5–7.5 µm [
55];
R. fontqueri by its multi-colored pileus but lacking purple tints [
64].
Mycobank—MB861808.
Etymology—refers to similarity to Russula delica in appearance of basidiocarps.
Holotype—CHINA. Shanxi Province: Lvliang City, Jiaocheng Country, Pangquangou National Nature Reserve, on the ground in the mix-forest dominated by Quercus sp. and Picea asperata Mast., 1700 m, 30 July 2021, collected by J.C. Lv, N. Mao, Li F and J.Z. Cao CF1119 (BJTC FM1945).
Description—Basidiocarps medium to large sized. Pileus 5.5–13 cm diam, flat-hemispheric to applanate, depressed at center, margin non-striated, surface slightly viscid to dry, white (#ffffeb), spotted with yellow brown (#d3ac00) patches. Lamellae adnate to subdecurrent, dense, lamellulae frequently present in different length, furcations absent, white (#ffffeb) to cream (#ffdd35), edge entire, concolorous. Stipe robust, 2.5–5.5 × 1.6–3 cm, solid, subequal, slightly tapering at base; surface white (#ffffeb) to cream (#ffdd35) longitudinal rugulose, but becoming smooth towards the base. Context 0.63–1.38 cm thick, white (#ffffeb). Odor not distinctive. Taste slightly salty. Spore print white to cream.
Basidiospores [90/6/3] 6.2–8.7 × 5.3–7.5 μm (Q = 1.01–1.22, Qm = 1.11 ± 0.1), subglobose to broadly ellipsoid, ornamentation of isolated warts, or short ridges, 0.5–1.3 μm high, sometimes interconnected into discontinuous reticulum, amyloid, hilar region with reduced ornamentation; hilar appendix (0.5)0.7–1.3(1.9) μm, pseudoamyloid. Basidia (40.9)43.6–56.2(59.5) × 9–11.7 μm, clavate, 2–4-spored, sterigmata 1.9–7.2 μm long, hyaline in 5% KOH. Pleurocystidia (54.8)63.1–85.3 × (6.4)6.8–8.8(9.2) μm, elongated clavate to clavate, medially slightly inflated, apex occasionally mucronate (≤6 μm), containing granular inclusions, gray in sulphovanillin. Cheilocystidia 41.4–65.5(70.4) × 5.8–8.1(11.3) μm, clavate-ventricose, containing granular inclusions. Lamellar trama irregular, composed of interwoven hyphae, Subhymenium 9.3–16.8 μm thick, composed of interwoven hyphae. Pileipellis metachromatic in Cresyl blue, two-layered, suprapellis ixocutis, 17.2–23.8 μm thick, hyaline in 5% KOH, terminal cells 16–30.5(34) × 2.7–5.5(6.4) μm, hyaline, clavate to ventricose; subpellis ixocutis, 48–65.5 μm thick. Pileocystidia 29.3–44.7(51.8) × 4.6–7.9 μm, clavate to ventricose, containing granular inclusions. Terminal cells of stipitipellis clavate. Caulocystidia (40.5)48.6–71.8(76) × 5.1–6.6 μm, clavate to lageniform, with granular inclusions. Clamp connections absent.
Habitat—Solitary or scattered on the ground in a mixed coniferous and broad-leaved forest dominated by Quercus liaotungensis and Picea asperata.
Additional specimens examined—CHINA. Shanxi Province: Lvliang City, Jiaocheng Country, Pangquangou National Nature Reserve, on the ground in the mix-forest dominated by Quercus sp. and Picea asperata Mast., 1900 m, 30 July 2021, collected by J.C. Lv, N. Mao, Li F and J.Z. Cao CF1119 (BJTC FM1965); ibid, Xinzhou City, Fanshi Country, Yantou Town, Erqielan Village, 2204 m, 12 August 2023, collected by H.Y. Fu, H.M. Ji and Y. Li. MS106 (BJTC FM3053).
Comments: Russula sinodelicata is characterized by its large basidiomata, white pileus with brown spots, adnate to subdecurrent lamellae, small basidiospores, and the unique association with Picea spp.
Russula sinodelicata is highly similar to the North American native
R. brevipes and the European native
R. delica as all of the three species possesses large and white basidiocarps. However,
R. brevipes is differentiated from
R. sinodelicata by its whitish to dull ivory pileus with ochraceous tones, decurrent lamellae showing white when young but becoming pale yellow to buff with age, and relatively large spores ((8.3)8.5–10.4(12.0) × (6.8)7.0–8.8(9.0) μm) [
65];
R. delica by its larger spores up to 8–12 × 7–9 μm and association with
Pinus spp. [
66].
Phylogenetically,
R. sinodelicata is classified in the subgen.
Brevipes (
Figure 1 and
Figure 2) and related to
R. australis,
R. byssina,
Russula pumicoidea (
Figure 1), and
R. sinuata, yet shows morphological distinctions.
Russula byssina possesses a creamy white to pale brownish-orange pileus and adnate to slightly decurrent lamellae [
67];
R. sinuata,
R. australis, and
R. pumicoidea are all sequestrate fungi lacking typical agaricoid basidiocarps, all of which are completely different from those in
R. sinodelicata [
68,
69].