Diderma chondrioderma (de Bary & Rostaf.) G. Lister (1925: 258)

Moreno, G., Castillo, A. & Thüs, H., 2024, Critical revision of Physarales and Reticulariales (Myxomycetes) at the Natural History Museum London (BM), Phytotaxa 644 (2), pp. 79-101 : 95-96

Diderma chondrioderma (de Bary & Rostaf.) G. Lister (1925: 258)

= Diderma arboreum G. Lister & Petch , in G. Lister (1913: 2)

Lectotype (designated by Lado & Wrigley de Basanta 2018):— SRI LANKA (Ceylon). Peradeniya : Royal Botanical Garden , 7º16’16”N 80º35’44”E, on bark of living trees, 27 Aug 1906, J. Petch 75, B.M. 3512 [ BM001089753 !]. Syntype:— UNITED KINGDOM. Scotland: Aberdeen, Skene, Westhill , 57.154ºN 2.284ºW, on living trunks of Wych Elme ( Ulmus montana ), Nov 1913, Rev. W. Cran, B.M. 3514 [ BM001089892 !] .

The lectotype material is scarce and no slide for LM has been made; SEM pictures of the spores and their ornamentation have been taken from the syntype only. The spores are collapsed and measure approximately 11 µm in diameter.

This species is characterised by the formation of sporocarps on mosses over tree bark, flattened, whitish plasmodiocarps, the capillitium formed by slightly purplish stout threads and by its large, spinulose spores, varying between (10–)12–13(–15) µm in diam. ( Martin & Alexopoulos 1969, Poulain et al. 2011), and in a wider range of 10–15 µm in diam. ( Lister 1925). The latter author corrects the description of D. arboreum and indicates that it corresponds to D. chondrioderma , thus treating it as a synonym ( Lister 1925).