Lycogala convexum W. L. Song, Yang Gao, Leontyev & 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 convexum W. L. Song, Yang Gao, Leontyev & Shuang L. Chen sp. nov.

Fig. 6

GenBank accession numbers.

PQ 685911 (SSU) and PQ 728373 (COI).

Etymology.

Convexum (Latin) convex, referring to the shape of peridial vesicles.

Diagnosis.

Differs from L. maculatum by convex, reddish-brown vesicles and the absence of bracelet-like ornamentation of the capillitium.

Description.

Sporocarps scattered or in small groups, more or less spherical, 1.5–3.5 mm in diameter. Peridium thin, membranous, pale beige-yellow, looking dark brown because of dense vesicle cover on the outer surface. The inner surface of the peridium smooth or covered with sparse warts. Vesicles under RL look like dried droplets, noticeably convex, with flattened periphery, rounded or slightly angular, wine red to rust red; under TL vesicles solitary, deep warm brown or darker t, semi-transparent, (120 –) 150–205 (– 280) μm in diameter. Vesicle walls thick, 5–15 µm, granular, single- or multilayered, with indistinct layer boundaries. Crystals mostly absent, but may be present and rather large. Oil droplets present, small to rather large, irregular in shape, strongly birefringent. Capillitium (2.1 –) 4.2–6.9 (– 10.8) μm in diameter, with uneven, wavy contour, but no clear bracelet-like thickenings, free end of tubules are swollen. The surface of capillitium ornamented with small warts and pits, accompanied by irregular ring-like inlets. Spore mass yellow with ochraceous undertones or darker in old collections, hyaline under TL, (5.0 –) 6.5–7.0 (– 7.5) μm in diameter, reticulate, with 4–5 meshes across diameter, unornamented area occupies 1 / 4–1 / 2 of the spore surface. Plasmodium unknown.

Distribution.

Currently known from China and South Korea.

Habitat.

On rotten wood.

Holotype.

CHINA • Jiangxi Province: Campus of Jiangxi Agricultural University , 28.7689°N, 115.8388°E, on rotten wood, 21 Oct 2019, collected by Yang Gao ( HFNNU 11245 ).

Additional specimens examined.

CHINA • Jiangxi Province: Campus of Jiangxi Agricultural University , 28.7670°N, 115.8375°E, on rotten wood, 14 Jul 2021, collected by Yang Gao ( HFNNU 11246 ) ; • Jiangxi Province: Guan Mountain National Nature Reserve , 28.5213°N, 114.6069°E, on rotten wood, 13 Sep 2024, collected by Xiao-Dong Liu and Yang Gao ( HFNNU 11243 ) ; • Jiangxi Province: Guan Mountain National Nature Reserve , 25.5185°N, 114.9119°E, on rotten wood, 13 Sep 2024, collected by Xiao-Dong Liu and Yang Gao ( HFNNU 11244 ) ; • Hubei Province: Shennongjia Forestry District , on rotten wood, 20 Aug 2015, collected by Shu-Zhen Yan, Gang He, Yang Gao, Xi Lin, and Gao-Wei Wang ( MCCNNU 2018 ) . SOUTH KOREA • South Gyeongsang: Forest on Jiri Mt , 35.336°N, 127.73°E, on rotten wood, 16 Jul 2007, collector unknown ( TNSM 13641 ) .

Notes.

Lycogala convexum resembles L. maculatum , although these species are not closely related. Both taxa have relatively large sporocarps, densely covered by dark solitary vesicles. However, in L. maculatum , both peridium and vesicles are usually darker than in L. convexum . Vesicles in L. maculatum are nearly flat, while in the new species they are clearly convex. Finally, L. convexum does not have bracelet-like thickenings on the capillitium, which are typical of L. maculatum and related Lycogala projectum (see below). From a phylogenetic perspective based on SSU and COI sequences (Fig. 2 ), the six specimens representing L. convexum form a separate clade (UBS = 100, PP = 1), sister to L. alisaulianovae and Lycogala roseoporum (UBS = 90, PP = 0.912). Both related species share with L. convexum the general type of the vesicle cover, but differ by the color of the spore mass. The interspecific genetic distance from L. convexum to L. roseoporum is 0.19, and to L. alisaulianovae is 0.25.

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 6. Morphological characteristics of Lycogala convexum: A – C sporocarps; D the outer surface of the peridium; E sporocarps; F peridial vesicles; G the inner surface of the peridium (SEM); H the detail of capillitium ornamentation (SEM); I capillitium; J the branch of capillitium (SEM); K the detail of capillitium ornamentation (SEM); L spores; M spore (SEM). Scale bars: 1.5 mm (A, B); 1 mm (C – E); 100 μm (F); 5 μm (G, H, M); 10 μm (I – L).