Didymium laxifilum G. Lister & J. Ross, 1943

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 laxifilum G. Lister & J. Ross , in G. Lister, Essex Naturalist 27(10): 264. 1945

— Lectotypus (designated by Moreno et al., Cryptogamie Mycol. 18: 316. 1997): UNITED KINGDOM. England, Loughton , Epping Forest, 51.55ºN 0.02ºE, on dead leaves, 19 Jan 1944, G. Lister & H.J. Howard ( BM 3501 ) [this collection is designated as the lectotype and is deposited in K(M)38221] . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, 19 Jan 1944, J. Ross ( BM 3500 !, BM000500877 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, 24 Feb 1944, J. Ross ( BM 3502 !, BM001089801 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, Aug 1944 ( BM 3503 !, BM001089802 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, 27 Jul 1944 ( BM 3504 !, BM001089803 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, Aug 1944, ( BM 3505 !, BM001089811 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, 21 Dec 1944 ( BM 3506 !, BM001089804 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, 30 Aug 1944, J. Ross ( BM 4172 !, BM001089812 + one slide with the same number but dated 2.X.1943, BM001247123 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, 27 Jul 1944, J. Ross ( BM. 4173!, BM001089810 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, Sep 1944 ( BM s.n.!, BM001089806 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, Sep 1944 ( BM s.n.!, BM001089809 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, Oct 1944 ( BM s.n.!, BM001089807 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, Oct 1944 ( BM s.n.!, BM001089808 ) . Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, Feb 1935, J. Ross (one slide BM s.n.!, BM001247124 ) . Syntypus: ( UNITED KINGDOM. England, Essex, Loughton, Epping Forest, The Warren , 51.66ºN 0.05ºE, Oct 1938, W.D. Graddon (one slide BM s.n.!, 2, BM001247125 ). Syntypus: UNITED KINGDOM. England, Essex, Loughton, Epping Forest , The Warren, 51.66ºN 0.05ºE, 21 Sep 1943, J. Ross (one slide BM s.n.!, 3, BM001247126 ).

BM 3500 / Didymium / laxifilum G. Lister & Ross / The Warren/ Loughton, Essex / 19.1.44. NXLVIII.76/ Coll. J. Ross./ BM000500877 [on a sheet label signed by Jun Matsumoto in August 12, 1998: “ Didymium laxifila G. Lister et J. Ross , Essex. Nat. 27: 263, 1945./ = Didymium aurantipes Brooks et Kowalski, Mycologia 58: 169, 1966./ Locality: The Warren, Loughton, Essex. Date: Jan.19, 1944. Leg.: J. Ross. NXLVIII.76. 3500./ (BM 000500877)/ This specimen is a paratype of Didymium laxifila G. Lister et J. Ross (See Moreno, Castillo, Illana and Lizárraga,/ 1977, Cryptogamie Mycol. 18: 315–325)./ Note: Lectotype of Didymium laxifila is deposited in K (Loughton, Epping Forest. Jan.19, 1944. Leg. J. Ross 3501./ [K(M)38221]). Other paratypes of this species in BM: The Warren, Loughton, Essex, 30 Aug. 1944, J. Ross/ 3505; The Warren, Loughton, Essex, 30 Aug. 1944, J. Ross n. s. (BM4172); The Warren, Loughton, Essex, 27/ July 1944, J. Ross n. s. (BM4137); The Warren, Loughton,/ Essex, 1944, J. Ross 3502; The Warren, Loughton,/ Essex, 1944, J. Ross 3503; The Warren, Loughton,/ Essex, 1944, J. Ross 3504; The Warren, Loughton, Essex,/ 1944, J. Ross 3505; The Warren, Loughton,/ Essex, 1944, J. Ross 3506; The Warren, Loughton, Essex, 1944, J./ Ross 3508.”]. [BM] 3502 / Didymium laxifila G. Lister & Ross / The Warren, Loughton, leg. J. Ross/ Feb 24, 1944 / NXLVIII.76/ BM001089801. [BM] 3503 / Didymium laxifila / G. Lister & Ross/ The Warren, Loughton, Essex,/ August, 1944./ NXLVIIIp87 A./ BM001089802. [BM] 3504 / Didymium / laxifila G. Lister & Ross / (BM. 4173)/ short stalked,/ July 27, 1944 N.XLVIII.85/ The Warren, Loughton,/ Essex Naturalist XXVII. Pl.X.p 263/ BM001089803. [BM] 3505 / Didymium laxifila / G. Lister & Ross/ The Warren, Loughton, leg. J. Ross/ Aug. 1944./ NXLVIII.87./ Examined 23/9/50 HJH. [H. J. Howard]/ BM001089811. [BM] 3506 / Didymium laxifila G. Lister & Ross / The Warren, Loughton, Essex,/ Dec. 21, 1944 /?X.2./ BM001089804. BM 4172 / Didymium laxifila / G. Lister & Ross/ The Warren, Loughton, Essex / From greenish plasmodium, 30 Aug. 1944 / leg. J. Ross/ see Essex Naturalist XXVII. Pt.Xp.163./ 1944 – 5/ BM001089812. + one slide with the same number but dated 2.X.1943 (BM001247123). BM. 4173 / Didymium laxifila / G. Lister &

Ross/ The Warren, Loughton,/ Essex / leg. J. Ross, 27 July, 1944/ see Essex Naturalist, XXVII. Pt.X.163./ 1944 – 5/ BM001089810. BM s.n. Didymium laxifila / G.L. & R./ The Warren, Loughton,/ Essex,/ Sept. 1944 / BM001089806. BM s.n. Didymium laxifila / The Warren, Loughton,/ Essex,/ Sept. 1944 / BM001089809. BM s.n. Didymium laxifila / The Warren, Loughton,/ Essex,/ Oct. 1944 / BM001089807. BM s.n. Didymium laxifila / G.L. & R./ The Warren, Loughton, Essex,/ October, 1944/ BM001089808. BM s.n. one slide 1/ Didymium / laxifila G. Lister / Ross/ The Warren/ Loughton J. Ross/ 2.1935, spores 11–12μ/ capm. a dark net/ XLVI.119/ BM001247124. BM s.n. one slide 2/ Didymium / laxifila G. Lister & Ross / The Warren/ Loughton, X.1938 / W.D. Graddon/ Capm. a dark network/ XLVIII.8/ BM001247125. BM s.n. one slide 3/ Didymium / laxifila/ G. Lister & Ross/ Warren, Loughton/ 21.9.1943, J. Ross/ XLVIII.65/ BM001247126.

NOTES: G. Lister (1945: 264) commented that “During the past few years an interesting form of Didymium has been found repeatedly in Epping Forest, near the Warren, Loughton. It occurs rather deep down in heaps of dead bramble, beech and other leaves” and added later “This form was first collected by Mr. Joseph Ross in February, 1935, and he has found it repeatedly and often in some abundance in various places in the same neighbourhood in the autumn of 1943, and in winter, summer and autumn of 1944. It was also found by Mr. W. D. Graddon in October, 1938 “near Woodford Wells.”. There are 12 boxes in BM labelled “Type collection” from the same place on different dates, all collected prior to the date of publication. Some have been examined by Moreno et al. (Cryptogamie Mycol. 18: 315–325. 1997) and by J. Matsumoto (who left a sheet label), but they consider these to be “ paratypes ”. However in the original publication no holotype has been designated therefore these collections must be syntypes. Matsumoto comments that the lectotype is in K (Loughton Forest. Jan. 19, 1944, leg. J. Ross 3501 [K(M)38221]. There are also 4 slides, one with number BM 4172 and the others with BM no number. The collections are commented upon and illustrated in the following notebooks ( XLVI: 118–119; XLVIII: 8, 63–65, 76, 85, 87). In K(M) 38221 there is the material from England, “dead leaves, J. Ross 3501”, that Moreno et al. (1997) considered to be the lectotype.