Didymium difforme var. repandum G. Lister, J. Bot.

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

Didymium difforme var. repandum G. Lister, J. Bot. 59: 91. 1921

= Didymium difforme (Pers.) Gray, Nat. arr. Brit. pl. 1: 571. 1821

— Lectotypus (designated here): UNITED KINGDOM. England, Bedfordshire , Chaul End, 51.863ºN 0.456ºW, 6 May 1897, A. Lister & G. Lister ( BM 1911 !, BM001089122 ) . Syntypus: UNITED KINGDOM. England, Bedfordshire , Chaul End, 51.863ºN 0.456ºW, May 1897, A. Lister & G. Lister ( BM 4008 !, BM001095265 ) . Syntypus: UNITED KINGDOM. England, Devon, Teignbridge, Teignmouth , 50.5515ºN 3.4886ºW, Mar 1916 ( BM s.n.!, BM001095266 + one slide BM s.n.!, 11, BM001247122 ) .

[BM] 1911 / Didymium difforme Duby / var. repandum / Broad & reticulate plasm./ Chaul End, Beds. 6.5.97/ A & GL/ BM/ N.XIVp.6/ BM001089122. BM 4008 / Didymium difforme Dub. / var. repandum G. List / Chaul End, Beds. May/ 1897./ leg. A. & G. Lister [label dated 3 FEB. 1927]/ BM001095265. BM s.n. Didymium / difforme/ v. comatum repandum G. Lister/ Teignmouth/ 3/1916/ seen by Miss Lister/ BM001095266/ N. G. HADDEN–presented 1956 + one slide 11, BM001247122.

NOTES: G. Lister (1921a: 91) wrote “This robust form has been obtained from Bedfordshire, Hertfordshire, Sussex, and South Devon, and seems worthy of varietal distinction.”. Collection BM 1911 is from Bedfordshire, and is designated as the lectotype, as it is material mentioned in the original publication, representative of the species and in good condition. In notebook XIV: 6, written on the label, we found notes and drawings of this collection and the number “Box 1911”. There is another collection from the same locality and collectors (BM 4008) but with no notebook reference. We regard this as a syntype as it is possible that it is a duplicate of the lectotype. Another collection with no box number is from Devon and a date prior to the publication. We regard this as another syntype. There is a slide (11) from this collection. This var. repandum “broad” is characterised by its sinuous broad plasmodiocarps or forming a flat peforated plate, is now considered to be a synonym of D. tubulatum E. Jahn , a species recognised by European authors ( Nannenga-Bremekamp 1975, Poulain et al. 2011) but not American researchers ( Martin & Alexopoulos 1969) who include it in their species concept of D. difforme .