Russula bella Hongo, Memoirs of Shiga University 18:50 (1968)

Wisitrassameewong, Komsit, Park, Myung Soo, Lee, Hyun, Ghosh, Aniket, Das, Kanad, Buyck, Bart, Looney, Brian P., Cabon, Miroslav, Adamcik, Slavomir, Kim, Changmu, Kim, Chang Sun & Lim, Young Woon, 2020, Taxonomic revision of Russula subsection Amoeninae from South Korea, MycoKeys 75, pp. 1-29 : 1

Russula bella Hongo, Memoirs of Shiga University 18:50 (1968) Figs 3A, B , 4A, B , 5

Diagnosis.

Pileus medium-sized, 20-50 mm diam., plano-convex to convex when young, applanate with depressed center to infundibuliform when mature, often lobate, margin with short striation, sometimes cracking in age; cuticle smooth, pruinose, viscid and shiny when wet, cuticle peeling approximately to half of the pileus radius or sometimes almost to the center, color variable, typically darker at the disk, greyish red (11D5), brownish violet (11D6) to bluish red (12A6-A8, 12B7), few with yellowish brown spots, margin pink (11A5) to greyish rose (11B5). Lamellae 2-3 mm deep, brittle, adnate, approximately 11-19 per cm near the pileus margin, moderately distant to crowded, yellowish white to pale cream; lamellulae absent; edge entire and concolorous. Stipe 17-34 × 5-9 mm, centrally attached or eccentric, cylindrical to slightly tapered towards the base, surface dry, longitudinally striate, whitish with a pinkish flush; solid when young, becoming hollow in age. Context 1-3 mm thick near the stipe, white, unchanging after cutting, turning greenish with FeSO4, turning quickly yellow with KOH, pale violet with PDAB; taste mild; odor slightly fruity. Spore print pale cream to white.

Basidiospores (n = 60, 3, 3) (6-)6.5-7.1-7.7(-8.8) × (5-)5.3-5.7-6(-6.6) µm, broadly ellipsoid, Q = (1.11-)1.17-1.25-1.33(-1.49), ornamentation thin, 0.4-1 µm high ridges forming an incomplete reticulum (2-7 in a 3 µm circle) with some dispersed isolated warts (0-2 warts in a 3 µm circle), suprahilar spot not amyloid, smooth. Basidia (25.1-)30-35.3-40.5(-48) × (7-)8.5-9.4-10.5(-11.5) µm, 4-spored, narrowly clavate, with guttate or granular contents. Basidiola (27.3-)28.4-32-35.5(-41.7) × (8.1-)8.7-9.4-10.3(-10.6) µm, narrowly clavate, with guttate or granular contents. Hymenial cystidia on lamellae sides inconspicuous, widely dispersed, up to 100 per mm2, (37.5-)52-63.5-75(-90) × (5.5-)7.5-9-10.5(-11.5) µm, clavate to subcylindrical, originating from subhymenium, apically obtuse, thick-walled with walls up to 0.8 µm; contents optically empty, negative in sulfovanillin. Lamellar edge with dispersed basidia, true gloeocystidia (with differentiated contents) absent; marginal cells very abundant, resembling terminal cells in the pileus, typically narrowly lageniform or subulate (24-)38.5-50.8-63(-83) × (4-)5.5-6.8-7.5(-9.5) µm; shorter clavate to subcylindrical with obtuse apex present, (9-)12.5-15.7-18.5(-23.5) × (3.5-)4.5-5.7-7(-7.5) µm. Pileipellis orthochromatic in Cresyl blue, trichoderm, sharply delimited from the underlying context, 280-400 µm thick, with a well-defined, gelatinized, 150-200 µm thick suprapellis of ascending or erect hyphal terminations forming a trichoderm, subpellis 130-200 µm thick, dense, horizontally oriented, sldender and gelatinized hyphae; acid-resistant incrustrations absent. Hyphal terminations near the pileus margin unbranched, often slightly flexuous, either long and attenuated or subcylindrical and obtuse, the attenuated ones more abundant, with terminal cells (20.5-)47-61.4-76(-85) × (3.5-)5-5.9-7(-8) µm, subulate or narrowly lageniform, rarely fusiform, apically acute to subacute, thin-walled, usually followed by 1-2 shorter and often more inflated cells before the branching; subcylindrical ones shorter, with terminal cells (7.5-)33.5-51.2-69(-107.5) × (2-)3.5-4.7-6(-7) µm, frequently originate from branched cells, sometimes with one shorter unbranched subterminal cell. Hyphal termination near the pileus center also dimorphous, the attenuated ones with terminal cells (10.5-)18.5-50.5-82.5(-104.5) × (3.5-)4.5-6.0-7.5(-10) µm, mainly subulate, occasionally narrowly fusiform, apically acute and sometimes acute-pointed, often with thickened walls (up to 0.8 µm), shorter cylindrical hyphae with terminal cells (9-)12.5-18.6-24.5(-32) × (2.5-)3-4-5(-6) µm; followed by 1-3 unbranched shorter cells, subterminal cells not usually not distinctly wider. Pileocystidia absent. Cystidioid or oleipherous hyphae in subpellis or context absent.

Ecology.

gregarious to scattered on soil in mixed forest with Quercus aliena , Pinus densiflora , and Populus sp.

Studied materials.

South Korea. Jeollanam-do, Haenam-gun, Mt. Duryun, 614 m elev., 34°27'24"N, 126°37'07"E, Yang Seop Kim, 5 September 1985, HCCN1457A (HCCN!); Chungcheongbuk-do, Danyang-gun, Mt. Sobaek, 790 m elev., 36°57'29"N, 128°26'35"E, Soon Ja Seok, 13 July 2007, HCCN15410 (HCCN!); Gyeonggi-do, Suwon-si, Seonggyungwan University, 58 m elev., 37°17'42"N, 126°58'22"E, Soon Ja Seok, 1 August 2008, HCCN16735 (HCCN!); Gangwon-do, Wonju-si, 275 m elev., 37°19'59"N, 127°54'35"E, Soon Ja Seok, 6 August 2008, HCCN16818 (HCCN!); Gyeonggi-do, Suwon-si, Seonggyungwan University, 48 m elev., 37°17'28"N, 126°58'24"E, Hye Yeong Choi, 5 August 2011, HCCN21655 (HCCN!); Daejeon-si, Yuseong-gu, 105 m elev., 36°23'48"N, 127°20'13"E, Myung Soo Park, 31 July 2012, SFC20120731-02 (SFC!); Gyeongsangbuk-do, Ulleung-gun, Mt. Seonginbong, 420 m elev., 37°30'50"N, 130°52'10"E, Seung-Yoon Oh, Won Ju Kim, Young Woon Lim, 14 August 2012, SFC20120814-23 (SFC!); Chungcheongnam-do, Seosan-si, Yonghyeon Natural Recreation Forest, 151 m elev., 36°45'53"N, 126°36'10"E, Young Ju Min, Won Ju Kim, Hyun Lee, 10 October 2012, SFC20121010-06 (SFC!); Seoul, Gwanak-gu, Seoul National University, 103 m elev., 37°27'26"N, 126°56'59"E, Komsit Wisitrassameewong, 31 July 2017, SFC20170731-02 (SFC!); ibid., 19 August 2017, SFC20170819-05 (SFC!).

Comments.

Russula bella is morphological similar to R. pseudoamoenicolor , R. punicea , and R. violeipes . Russula pseudoamoenicolor has a more vividly colored pileus and a larger basidiome and hymenial cystidia than those of R. bella ( Hyde et al. 2016). Russula punicea differs from R. bella in the shape of hymenial cystidia; the former has acute cystidia, whereas the latter has obtuse cystidia ( Chiu 1945; Hongo 1968). Russula violeipes differs from R. bella in the yellowish to greenish smeared violet color of the pileus ( Kränzlin 2005). Moreover, R violeipes has larger basidia (45-65 × 11-14 µm) and pleurocystidia (80-115 × 12-15 µm) than those of R. bella ( Kränzlin 2005).

Figures

Figure 3. Basidiomes of Korean Amoeninae from this study. A, B Russula bella (A-SFC 20170802 - 03, B-SFC 20170819 - 05) C-E R. orientipurpurea (SFC 20170819 - 08) F, G Russula sp. (SFC 20160726 - 13). Scale bars: 20 mm.

Figure 4. Basidiospores with scanning electron microscopy images (A, C, E) and drawing images (B, D, F) A, B Russula bella (SFC 20170819 - 05) C, D R. orientipurpurea; (SFC 20170821 - 22 b) E, F Russula sp. (SFC 20160726 - 13). Scale bars: 2 µm.

Figure 5. Microscopic features of Russula bella (SFC 20170819 - 05) A basidia B basidiola C clavate marginal cells D hymenial cystidia on lamellae sides E subulate marginal cells F hyphal termination at pileus margin G hyphal termination at pileus centre. Scale bars: 10 µm.