Lycogala nigrum W. L. Song & Shuang L. Chen, 2025

Song, Wen-Long, Jiang, Zi-Qiong, Li, Min, Leontyev, Dmytro, Gao, Yang & Chen, Shuang-Lin, 2025, Comprehensive revision of Lycogala (Myxomycetes) in subtropical China: morphological and phylogenetic insights and ten new species, IMA Fungus 16, pp. e 147535-e 147535 : e147535-

Lycogala nigrum W. L. Song & Shuang L. Chen sp. nov.

Fig. 11

GenBank accession numbers.

PQ 685932 (SSU).

Etymology.

Niger (Latin) black, referring to very dark, opaque peridial vesicles.

Diagnosis.

Differs from all other species in the genus by possessing peridial vesicles that appear black and opaque under transmitted light.

Description.

Sporocarps scattered, spherical, short horizontally oval, sometimes deformed by mutual pressure, 1.7–3.7 mm in diameter. Peridium membranous, thin, yellowish brown with olivaceous tones or lighter under RL, with dense vesicle cover, giving a nearly black appearance, the dehiscence area at the top of sporocarp conspicuous, free of vesicles, irregular in shape. The inner peridial surface smooth or covered with scattered warts. Vesicles black under RL, dark under TL, (117.6 –) 161.7–237.8 (– 269.2) μm in diameter, isodiametric, irregularly polygonal, solitary, but densely distributed. Oil droplets present, large or small, irregular in shape, reddish, concentrated in the central part of vesicles. Capillitium tubular, hyaline under TL, (5.1 –) 5.3–9.1 (– 19.8) μm in diameter, with smooth or somewhat wavy contour and no bracelet-like thickening, the surface of the thread is decorated with small warts and pits, and occasional ling-like islets, visible under TL and SEM. Spore mass in old collections yellow with ochraceous undertones or darker, hyaline under TL, (5.7 –) 6.0–6.2 (– 6.4) μm in diameter, reticulate, with 6–7 meshes across diameter, unornamented area occupies 1 / 4 of the spore surface. Plasmodium unknown.

Distribution.

Currently known only from China.

Habitat.

On rotten wood.

Holotype.

CHINA • Jiangsu Province: Zijin Mountain National Forest Park , 32.0628°N, 118.8761°E, on rotten wood, 10 Jun 2015, collected by Gao-Wei Wang and Shu-Zhen Yan ( HFNNU 11266 ).

Additional specimens examined.

CHINA • Anhui Province: Huang Mountain National Forest Park , 30.1421°N, 118.2071°E, on rotten wood, 5 Jul 2008, collected by Shuang-Lin Chen ( HFNNU 11267 ) .

Notes.

To our knowledge, among all 23 described species of Lycogala ( Lado 2005–2025), there is not a single species in which vesicles appear black and opaque under TL ( Leontyev et al. 2023 b). This makes L. nigrum unique in this regard. From a phylogenetic perspective (Fig. 2 ), the two specimens representing L. nigrum form a separate clade (UBS = 100, PP = 1) related to L. alisaulianovae and L. roseoporum (UBS = 76). These two species share dark solitary vesicles with L. nigrum , but in both of them these structures are not opaque. The interspecific genetic distance between L. nigrum and the other species in this clade, measured based on SSU sequences, is 0.36. The separation of L. nigrum is supported in all partitions created by ASAP (Suppl. material 7).

Figures

Figure 2. Maximum likelihood tree inferred from the concatenated sequences of SSU and COI, showing the phylogenetic relationship of Lycogala. The members of Reticularia were used to root the tree. Only Maximum likelihood ultrafast bootstrap support (UBS) / Bayesian posterior probabilities (PP) ≥ 70 / 0.7 are shown. The voucher numbers are indicated after the species names. The number of identical genotypes is in parentheses (if present). The ten new species described in this study are indicated in red and bold. The four new species to China are indicated in blue and bold. Other newly obtained sequences are in bold. The scale bar represents the number of substitutions per site.

Figure 11. Morphological characteristics of Lycogala nigrum: A sporocarp; B the outer surface of the peridium; C, D peridial vesicles; E the inner surface of the peridium (SEM); F the branch of the capillitium (SEM); G capillitium; H the detail of capillitium ornamentation (SEM); I spores; J spores (SEM). Scale bars: 1.5 mm (A); 1 mm (B); 100 μm (C, D); 5 μm (E, H, J); 10 μm (F, G, I).