Comatricha macrospora B. Zhang & Yu Li, 2018

Zhang, Bo, Wang, Saiyu, Xu, Xiaoqi, Li, Tianhao, Dai, Dan & Li, Yu, 2018, Identification of the new species Comatricha macrospora and two other recently recorded species of Comatricha from China, Phytotaxa 374 (1), pp. 71-79 : 74-75

Comatricha macrospora B. Zhang & Yu Li , sp. nov. Figure 2 .

MycoBank number: MB 824130.

Cylindrical dark brown sporocarps are present in tufts, with a total height of 5–7 mm. The stalks are short or absent and often appear to be polished black. The sporothecae are oval, rounded at the apex and dark brown. A persistent peridium at the base of the sporotheca has a single layer that is partly evanescent; the peridium is dark black, with a dehiscence that is apical and irregular. The columella usually arrives at the apex of the sporotheca, fused with the capillitium. The internal net of the capillitium consists of thick threads with several, usually large, expansions at the junctions; mostly exceeding 50 μm, typically in the form of thin threads without free ends. A mass of dark brown spores, 11–14 μm in diameter, are densely, evenly and minutely warted.

Diagnosis:— Smaller sporocarps, persistent peridium at the base of the sporocarps and larger spores than other species in this genus.

Typification:— CHINA. Jinlin Province, Baishan City, Changbai Mountain National Nature Reserve, on a rotting log in a mixed forest, 18 October 2017, Zhang 25382 (Holotype, HMJAU-M1066!). GenBank: SUB3594089.

Etymology:— macrospora (Lat.) : referring to the larger spores.

Other specimen examined. — CHINA. Jilin Province, Chibei County, on a rotting log in a mixed forest, 22 August 2015, Zhang 13462 (Paratype, HMJAU-M2066!)

Discussion: About 42 species of Comatricha have been reported worldwide ( Kirk et al. 2008, Lado 2001, 2005– 18), of which nine species have reticulate spores and 33 species have spiny or verruculose spores. Of the accepted species, only C. pseudoalpina G. Moreno, H. Singer , A. Sánchez & Illana and C. filamentosa Meyl. are similar to C. macrospora in having a persistent peridium and sporothecae that are subcylindric and somewhat expanded in their upper portions. However, C. pseudoalpina has smaller spores (10–12 μm in diameter), larger sporothecae (1.5–2.5 mm) and warted capillitium threads. Comatricha filamentosa has an expanding capillitium that becomes entangled with the adjacent capillitia and minutely spinulose spores (10–13 μm in diameter).

Figures

FIGURE 2.. Comatricha macrospora B. Zhang & Yu Li (HMJAU-M1066!) A. Sporocarp growing on a log; B. Sporocarp as seen by SEM, C. Columella and capillitia; D. Capillitia and spores as seen by TL; E. Peridia and capillitia; F. Spores marked with spines. (Bar: A = 2 mm)