Licea pygmaea ( Meylan 1933: 89 ) Ing (1982: 443)

Bortnikov, Fedor M., Gmoshinskiy, Vladimir I. & Novozhilov, Yuri K., 2022, Species of Licea Schrad. (Myxomycetes) in Kedrovaya Pad State Nature Biosphere Reserve (Far East, Russia), including two new species, Phytotaxa 541 (1), pp. 21-48 : 38

Licea pygmaea ( Meylan 1933: 89) Ing (1982: 443) Fig. 15 .

Description:—Sporocarps gregarious, small, 130–260 µm in diameter, black (267). Peridium concolorous, usually consists of 4–6 plates, yellowish-brown, reddish-brown to greenish olive (125) by transmitted light. Inner peridium covered with small warts, plates margins with outgrowths and warts. Spores dark olive (108) to black (267) in mass, olivaceous brown (95) by transmitted light, with unevenly thickened wall, (9.5–) 10.7–12.2 (–13.3) µm in diameter, warted.

Material examined:— LOC 3 (MYX 8201), LOC 5 (MYX 8272), LOC 12 (MYX 10237), LOC 14 (MYX 10242, MYX 10249), LOC 15 (MYX 10265), LOC 16 (field specimen MYX 11331, it was found together with Stemonitis axifera ), LOC 19 (MYX 10289), LOC 25 (MYX 10297, MYX 10298, MYX 10299), LOC 26 (MYX 11321), LOC 28 (MYX 11325) .

Habitat:—oak and coniferous forests, on rotten wood, plant litter, and bark of living trees ( Abies holophylla , Pinus koraiensis and Quercus mongolica ), pH: 4.13–5.90 (n = 10).

Notes:—Our L. pusilla and L. pygmaea specimens are very similar in size, shape, and color of sporocarps, in dehiscence type, and in color and ornamentation of spores. The features commonly used to separate these species are the spore size (larger spores in L. pusilla ) and the inner peridium ornamentation (almost smooth in L. pusilla vs. warted in L. pygmaea ) (Ing 1999). The spores of our specimens are indeed somewhat different, 9.5–13.3 μm in L. pygmaea vs. 12.8–19.4 μm in L. pusilla ; however, these ranges overlap ( Fig. 16 ). Moreover, we found no stable differences in the inner peridium structure. Generally, in our L. pygmaea specimens, warts on the peridium inner surface are larger (0.15–0.20 μm) and have complex structure ( Fig. 15 H, I ); in L. pusilla specimens, the warts are about 0.1 μm and have simple structure ( Fig. 14 G, H ) (which is consistent, for example, with the study of Gilert 1996, Figs. 4 and 6 ). However, there are also L. pusilla specimens with composite large warts ( Fig. 14 F ). Outgrowths and warts on the margins of peridial plates in L. pusilla are often quite large and arranged in a single row ( Fig. 14 D, E ), and in L. pygmaea , they are smaller and often arranged in 2–3 rows ( Fig. 15 E, F ). However, this feature is not completely stable either ( Fig. 15 D ).

The rank of Licea pygmaea was raised to the species level (from L. pusilla var. pygmaea Meyl. ) by Ing (1982), who wrote: “As varieties tend to be overlooked in most floristic works, they are often under-recorded and not studied sufficiently. In view of the differences between L. pusilla and L. pygmaea it seems not unreasonable to raise var. pygmaea to specific rank in the hope that more collections will be made”. However, the author himself mentioned that Martin & Alexopoulos (1969) and Nannenga-Bremekamp (1965) reported the existence of transitional forms. Nannenga - Bremekamp (1965) stated that there are specimens with intermediate spore size of approximately 14 μm (which our data also supports, see MYX 8233, MYX 8270 and MYX 8271 on Fig. 16 ). Lado et al. (2011) wrote about L. pygmaea specimens with the almost smooth inner peridium, with the exception of a small number of warts on the edges. At the same time, we have a L. pusilla specimen, MYX 11014, with rather large warts on the inner peridium ( Fig. 14 F ). Our L. pusilla and L. pygmaea specimens almost do not differ by the sporocarps size. All these facts, in our opinion, confirm the hypothesis that L. pusilla and L. pygmaea could belong to the one greatly variable species or a group of species, and additional studies are required in order to determine their status.

Figures

FIGURE 4. Licea biforis (MYX10115: a, b; specimen recorded only by photo: c). a–b: Sporocarps. c: Spores by TL. Scale bars: a, b = 100 µm, c = 20 µm.

FIGURE 6. Licea craterioides (MYX10060). a, b: Sporocarps. c: Spores by TL. d: Peridium under SEM. e: Peridium and spores under SEM. Scale bars: a, b = 100 µm, c = 20 µm, d, e = 10 µm.

FIGURE 14. Licea pusilla (MYX8233: a, b, e, g, j; MYX8271: c, d, h, i; MYX11014: f, k). a–c: Sporocarps. d–e: Peridium and spores by TL. f–h: Inner peridium under SEM. i: Inner ornamentation of the peridial plate margin. j–k: Spores under SEM. Scale bars: a–c = 100 µm, d = 20 µm, e = 10 µm, i–k = 5 µm, f–h = 1 µm.

FIGURE 15. Licea pygmaea (MYX8201: f; MYX8272: d; MYX10237: a, c, h, k; MYX10249: e; MYX10289: g; MYX10297: b, i, j). a–c: Sporocarps. d–g: Spores and peridium by TL. h–j: Inner peridium under SEM. k: Spores under SEM. Scale bars: a–c = 100 µm, d–g, j = 20 µm, k = 5 µm, h, i = 1 µm.

FIGURE 16. Licea pygmaea and L. pusilla spore size. For each specimen indicated 30 spores were measured.