Diderma arboreum G. Lister & Petch, 1913

Lado, Carlos & Basanta, Diana Wrigley De, 2018, Typification of the myxomycete taxa described by the Listers and preserved at the Natural History Museum, London (BM), Phytotaxa 341 (1), pp. 448-450 : 448-450

Diderma arboreum G. Lister & Petch , in G. Lister, J. Bot. 51: 2. 1913

= Diderma chondrioderma (de Bary & Rostaf.) G. Lister , in Lister, Monogr. mycetozoa, ed. 3, 258. 1925

— Lectotypus (designated here): SRI LANKA (Ceylon). Peradeniya, Royal Botanical Garden , 7º16’16”N 80º35’44”E, on bark of living trees, 27 Aug 1906, J. Petch 75 ( BM 3512 !, BM001089753 ) [In the same box there is a second old label, probably the original label] . Syntypus: UNITED KINGDOM: Scotland, Aberdeen, Skene, Westhill , 57.154ºN 2.284ºW, on living trunks of Wych Elme ( Ulmus montana ), Nov 1913, Rev. W. Cran ( BM 3514 , BM001089892 ) .

BM 3512 Diderma arboreum G. Lister & Petch / On bark of living trees, R. Bot. Gardens,/ Peradeniya, Ceylon, 27.8.1906,/ leg. J. Petch/ see Journ. Bot. Li.p.2 (1913) Tab. 524 fig. 2, 2a, b./ BM001089753 [sheet label dated 25 NOV. 1914. On the same sheet there is a second old label, probably the original label with: “Petch 75, 101/ Chondrioderma sp. / (arboreum)/ rugosum var. sessile ?/ Talawakelle, 3.8.05/ R.B.G. 27.8.06/ 186 117 p. 103, 151”]. BM 3514 / Chondrioderma (de Bary & Rost.) G. Lister / Diderma arboreum G. Lister & Petch / On living trunks of Wych Elm ( Ulmus / montana Sm. ), Westhill, Skene, Aberdeen/ Nov. 1913. Rev. W. Cran legit./ BM001089892.

NOTES: G. Lister (1913a: 2), in the original description, lists numerous collections, “It has been obtained from three widely separated regions— Ceylon, Japan, and Scotland. It was first found in May, 1906, by Mr. T. Petch in Ceylon, at

Peradeniya, 1600 ft. alt. and at Talawakelle, 4000 ft. alt.; and again at Paradeniya in August, 1906. …” “… In Japan,

Mr Kumagusu Minakata obtained similar sporangia in the summers of 1906, 1907, and 1909, in the province of Kii, on living trunks of Prunus Mume Sieb. & Zucc. , P. persica Sieb. & Zucc. , and Celtis sinensis Pers. …” “ … In Scotland,

thanks to the keen sight and perseverance of the Rev. W. Cran, many gatherings have been made in summer and autumn in the last three years on the living trunks of elder, sycamore, &c., both at Rhynie and Skene, Aberdeenshire.”. In BM

there are only two boxes (BM 3512, BM 3514). In box BM 3512 there are two samples, one from Peradeniya, Ceylon,

27.8.1906, J. Petch., that we designate as the lectotype, plus a small fragment with the number 101. The material is beautifully illustrated and commented upon in the notebook that is dedicated to Petch material sent to G.Lister. On pages 103– 104 specimen Petch 75 is illustrated and on pages 149–152 sample Petch 102. In the third edition of the monograph, Miss Lister (1925: 258) , noted in the section “Errata and adenda” “P. 86. For Diderma arboreum G. Lister

& Petch in Journ. Bot., li. 2 (1913) read D. chondrioderma G. Lister , nov. comb. ”.