Acta Botanica Neerlandica 13 (1964) 133-147 Notes on Myxomycetes VII N.E. Nannenga-Bremekamp (.Doorwerth) (:received October 23rd, 1963) As in with collected my previous papers dealing Myxomycetes by me in the Netherlands, here too the specimens dealt with are preserved either in in that of the Botanical Museum and my private collection, Herbarium of the State University, Utrecht (in the last-mentioned case the numbers are followed by a “U”), or in both. I am much Dr. W. indebted to Prof. G. Martin for sending me valuable specimens, and for his help, to the British Museum for the facilities accorded to me for studying its Myxomycete collections, and to Dr. R. Santesson of the Institute of Systematic Botany of the University of Uppsala for advice and the loan of valuable specimens. Cribraria Pers. Cribraria argillacea (Pers.) Pers.; Fig. 1 and 2. 15; 51 U; 123 U; 319 U; 429 U; 547; 569 U; 587 U; 688 U; 826 U; 1068; 1104; 1304; 1389; 1934; 1970; 2022; 2023; 2121; 2385; 2657; 2733; 2745; 2815; 2910; 2963; 2973; 2985; 3030; 3031; 3061; 3062; 3091; 3497; 4127; 4145 U; 4158; 4194; 4218; 4250; 4365; 4594; 4613 (cf. Fig. 2); 4935; 5230 all from decaying coniferous wood, Heelsum-Doorwerth; 608 U from decaying coniferous wood Bilthoven, leg. M. A. Nannenga; 1388 from decaying wood in a living oak, Bilt- hoven; 2013 on pine needles next to a pine stump, Doorwerth; 5189 (cf. Fig. 1) collection in moist chamber a small obtained a on moss growing on a piece of bark from a living oak, Wolfheze. Although variable, this species is, as a rule, not difficult to identify, even in the field. The sporangia are shortly stalked, usually crowded together, of a sandy yellow-brown colour with a delicate, silvery, of fugaceous peridium, which the lower part occasionally persists as The net is of flat a cup. usually fairly wide-meshed, consisting bands, which become broader towards the base, and which are connected by thin threads; at the base they sometimes form ribs. It is sometimes transmitted but be pale (ochraceous by light) Fig. 1, may nearly black (red-brown by transmitted light, with some dark granules with bright strongly refracting centres) Fig. 2; these dark bands often in in extend into the stipe the form of prominent ribs, more or less in C. that has different the same way as ferruginea, but species a quite colour (Fig. 4). Sometimes (15, 3091 and 2745), the typical C. argil- lacea net with its less bands is modified at the of more or even apex the and into of thin threads with small sporangia, passes a net nodes, like those of C. but that rather similar very oregona, species, although 133 134 N. E. NANNENGA-BREMEKAMP 1. Cribraria and of the Fig. argillacea, 5189; A, sporangium; B, spores a part peridial net. 2. Cribraria and of Fig. argillacea, 4613; A, sporangium; B, spores a part the peridial net, showing the dark granules with strongly refracting centres. NOTES ON MYXOMYCETES VII 135 in has lax of general appearance, a more persistent net consisting glossy threads with small dark nodes at the intersections. The threads in C. argillacea are never glossy. C. martinii (Fig. 7) too is rather similar, see under that species. The plasmodium is dark grey. Cribraria aurantiaca Schrad.; Fig. 3. 50; 155 U; 357 U; 554; 563 U; 589; 594; 606; 651 U; 672; 768; 803; 1058; 1059; 1071 (cf. Fig. 3); 1081; 1210 U; 1333; 1334; 1440; 1497; 1513; 1514; 1535; 1562; 1563; 1959; 1971-b; 2007; 2008 U; 2033; 2034; 2122; 2699; 2863; 2865; 2866; 2879; 3498; 3499; 3501; 4001; 4096; 4100; 4129; 4137; 4138; 4164; 4165; 4166; 4167; 4256; 4287; 4288; 4289; 4388; 4391 U; 4392; 4394; 4998 all on decaying coniferous wood Heelsum-Doorwerth; 606 leg. M. A. Nannenga, 1390, 1407, 2040, 4344, 4345, 4355 and 4371 from decaying coniferous wood, Bilthoven; 4400 from a decaying pine stump, Leersum. After Persoon (1801) had reduced Cribraria aurantiaca Schrader to a variety of C. vulgaris Schrader, in which Lister followed him, Macbride and Martin in their monograph (1934) united them under the name C. aurantiaca Schrad., which vision was shared by Hagelstein (1944). Careful of those of which the study my specimens to descriptions of these authors apply, and of some of those in the Listers’ collection at the British Museum (in this collection the note “var. aurantiaca” placed at the bottom of sheets containing both varieties is rather confusing) viz. C. aurantiaca B.M. 1430, and C. vulgaris B.M. 1431, well that of Schrader’s Gen. 2737 and 3622, as as descriptions (Nov. PI. 1797) has convinced me that Schrader’s species are sufficiently distinct to be retained. be known the They may apart by following brown and in C. characters. Hypothallus usually opaque aurantiaca, inconspicuous in C. vulgaris. C. aurantiaca is larger in all its parts than C. vulgaris. When fresh, C. aurantiaca is bright yellow, fading however the to an ochraceous dusty brown, against which numerous small C. the other dark nodes stand out; vulgaris, on hand, is hazelnut-brown, with the much fewer nodes for be not always conspicuous they may either pale or dark. In C. aurantiaca the peridium often persists on a of this part the sporangium, tinting this part rusty-brown; in case it is about third has dried feature which as though a prematurely, a is in C. The of both are striate never seen vulgaris. cups species by bands of granules; in C. vulgaris they are usually finely, concentrically wrinkled, whereas in C. aurantiaca these wrinkles are usually absent. The connections between the cup and the net are more numerous, longer, finer and simple in C. aurantiaca, while in C. vulgaris these are few, short, broad and toothed. The nodes of C. aurantiaca are less in the lower more or elongate part, numerous, small, convex and often rounded above; in C. vulgaris they are broad, flat, much branched, angular and few; both species have thin connecting threads, but these are shorter in C. aurantiaca, forming smaller meshes (the much 1-2 in The dictydine granules are alike, n diameter). spores of C. aurantiaca are 6-7 in have one or two /i diameter; they large, brilliantly refracting inclusions, probably consisting of etherial oil, 136 N. E. NANNENGA-BREMEKAMP which in but for in herbarium disappear time, keep years specimens if heated not too intensely for drying and disinfecting purposes, then be found in though even traces may usually specimens over ten years old (B.M. no. 1430 collected in 1888 still has them practically the intact); spores are so minutely spinulose as to appear smooth, the outline and dry spore (Fig. 3c), shows a more or less reniform under the The of C. 6.5-8.5 in microscope. spores vulgaris are fi diameter; they lack the yellow inclusions and are distinctly, though minutely spinulose; viewed under the microscope they have a some- 4-6 what angular outline, due to the presence of larger spinules on the circumference; connecting these there is a lax reticulation formed and of rows of spinules, which is often quite as conspicuous of the 3. Cribraria and node of the Fig. aurantiaca, 1071; A, sporangium; B, spores peridial net; C, spores. NOTES ON MYXOMYCETES VII 137 that in C. the of C. same type as seen dictyospora; dry spore vulgaris In 5 KOH shows a more or less “starry” outline (Fig. 12d). % or and nodes of C. aurantiaca but the NaOH, cup, net turn purple, not In C. the The of spores. vulgaris spores too turn purple. plasmodium C. aurantiaca is brilliant green, that of C. vulgaris dark grey. Of course Schrader could describe the neither did he not spore characters; mention the difference in the colour of the plasmodium (Lister does), but the characters described by him are correlated with these. See also under Cribraria vulgaris. Cribraria cancellata (Batsch) Nannenga var. cancellata. 113; 158 U; 159 U; 420 U; 731; 1023; 1191; 1916; 1951; 2672; 2732; 2739; 2829 from decaying wood, Heelsum-Oosterbeek, and 1382 from Bilthoven. The black plasmodia of this species, and also those of its variety fusca, are often large, commonly producing hundreds of sporangia, and often stain the wood from which On they they emerge purple. of the the ribs of the less dispersal spores more or globose sporangia turn inwards like those of a lobsterpot, except in those, rare, cases form the of the where they unite to a net at top sporangium. 4. Cribraria and of the Fig. ferruginea, 4402; A, sporangium; B, spores a piece of the further peridial net; C, part same, enlarged. 138 N. E. NANNENGA-BREMEKAMP cancellata Cribraria (Bätsch) Nannenga var. fusca (G. Lister) Nannenga. 8; 186; 284 U; 1041 U; 1051; 1070; 1133; 1243; 2635; 2703; 3355; 3832; 4031; 4919; 4928; 4972; 5177; 5203 from decaying wood, 4013 and 4428 developed in moist chambers on decaying coniferous wood, Heelsum-Oosterbeek. See note under var. cancellata. Cribraria ferruginea Meylan; Fig. 4. 4402, from a decaying pine stump, west of Leersum, 27-8-1960. A small, rather weathered colony on a conspicuous concolorous hypothallus. The ribs of the sporangia are very prominent in the lower third. This is sometimes seen in C. argillacea too, but that species may be known by its yellowish brown colour, while this is of a rich redbrown. Cribraria intricata, Schrader; Fig. 5 and 6. found Not by me in the Netherlands; the specimens doubtfully referred here in list all C. Prof. Dr. W. K. H. my are vulgaris. However, 5. Karstens Fig.