Russula callainomarginis J.F.Liang & J.Song

Xie, Xiu-Chao, Buyck, Bart & Song, Yu, 2023, Species of Russula subgenera Archaeae, Compactae and Brevipedum (Russulaceae, Basidiomycota) from Dinghushan Biosphere Reserve, European Journal of Taxonomy 864, pp. 28-63 : 49-52

Russula callainomarginis J.F.Liang & J.Song

Figs 9–10

Material examined

CHINA • Guangdong Province, Zhaoqing City, Dinghushan Biosphere Reserve , on the ground in evergreen broad-leaf forest mainly with Fagaceae trees; 10 Jun. 2018; Y. Song K18061013 ; GenBank nos: MN275693 (ITS), MN839582 (nLSU), MN839632 (mtSSU), MT085535 (rpb1), MT085659 (rpb2), MT085602 (tef1); GDGM79715 • same data as for preceding; 22 Apr. 2019; Y. Song K19042220 ; GenBank no: MN839555 (ITS); GDGM79716 .

Description

Basidiomata medium to large sized. Pileus 6–10 cm in diam., hemispherical to convex when young, turning applanate with depressed center to infundibuliform; surface glabrous, dry, viscid when wet, white to cream (#FFFAFA, #FFFFF0) with reddish brown (#F5DEB3, #F2E0B7) tint; margin slightly undulate and upward. Lamellae adnate to decurrent, unequal with multidymous lamellulae, often forked near stipe and pileus margin, interveined, white at first, turning cream with brown tint (#FEEABA, #FAEDB3) with maturity; edge entire, concolorous. Stipe central, subcylindrical, solid at first, turning hollow with age, 4–6 cm long, white, stained with reddish brown (#F9E197, #F2D782) when old, longitudinally rugulose. Context white. Odor distinct. Spore print whitish.

Basidiospores subglobose to ellipsoid, rarely globose, (40/2/2) (5.4–)5.7–6.3–7.1(–7.4) × (4.9–)5.2– 5.6–6.1(–6.5) µm, [Q = (1.03–)1.04–1.16–1.24(–1.36)], hyaline in 5% KOH; ornamentation amyloid, composed of verrucous to cylindrical warts less than 1 µm in height, some fused into short crests, mostly connected by fine lines forming partial reticulum; suprahilar spot amyloid. Basidia (25–)27– 29.5–32(–34) × 8–9.5–11(–12) µm, clavate, 2- or 4-spored, thin-walled; sterigmata 4–10.5 × 0.8– 1.6 µm. Pleurocystidia (23–)27–43–81(–101) × 5–7.5–10.5 µm, mostly typical fusiform, with obtuse, mucronate or papillate apices, thin-walled, with refractive contents mostly distributed in middle to upper parts, some subcylindrical, arising from deep in subhymenium, weakly positive in SV. Cheilocystidia (23.5–)26–33–39(–41.5) × (5.5–)6.5–7.5–10 µm, fusiform, with obtuse or mucronate apices, thinwalled, with refractive contents mostly at medium parts. Subhymenium pseudoparenchymatous. Lamellar trama composed of numerous sphaerocytes surrounded by connective hyphae, sphaerocytes measuring 10–28 × 7.5–23 µm. Pileipellis composed of ascending to erect hyphae, 100–140 µm thick; hyphae cylindrical, septate, hyaline, thin-walled, 1.5–5 µm wide; terminal cells (8–)10.5–19–35 × 2.5– 3.5–5.5 µm, cylindrical, rarely lageniform, with obtuse apices, hyaline, some incrusted. Pileocystidia (11–)26–55.5–80(–84) × 2–4–6(–7) µm, cylindrical to fusiform, with obtuse, mucronate to papillate apices, with granular refractive contents, unchanging in SV. Stipitipellis composed of cylindrical, septate hyphae measuring 1.5–4 µm wide; terminal cells cylindrical with obtuse apices, hyaline. Caulocystidia (16.5–)30–54–68(–74) × 1.5–4–6.5 µm, cylindrical, obtuse or papillate, with refractive contents. Clamp connections absent in all tissues.

Comments

Russula callainomarginis was recently described from China ( Song et al. 2022). Collections of this species from DHSBR are mostly in accordance with the original morphological descriptions, except that DHSBR specimens have obviously smaller basidia [(25–)27–29.5–32(–34) × 8–9.5–11(–12) µm] and pileocystidia unchanging in SV (turning dark grey to blackish when first described).

Figures

Fig. 9. Russula callainomarginis J.F.Liang & J.Song (GDGM79715).A–B. Fruiting bodies.C. Terminal elements in pileipellis. D–G. Basidia. H–I. Basidiospores under scanning electron microscope. Scale bars: A–B = 1 cm; C = 25 µm; D–G = 10 µm; H–I = 1 µm.

Fig. 10. Russula callainomarginis J.F.Liang & J.Song (GDGM79715). A. Basidia. B. Pleurocystidia. C. Cheilocystidia. D. Terminal elements in pileipellis. Scale bars = 10 µm.