Lepidoderma 137 



Habitat: On leaves, twigs, stems, etc. 



Distribution: *California, New Hampshire, *Oregon, Utah, 

 *Washington ; var. granuliferum, Cahfornia, Utah, *Washington. 



Illustration: Lister, Mycetozoa ed. 3. pi. 115. 



This species, its var. granuliferum, and L. ChaiUetii are difficult 

 to understand and separate, somewhat because of the rarity of 

 collection, but also because the impression prevails that the prin- 

 cipal distinctions are in the spore-characters. The spores in all 

 three forms exhibit considerable variation beside the size. The 

 color may be grayish or brownish, the spines stronger or fainter, 

 and the spores may be paler on one side or not. The forms are 

 more abundant in Europe, and there show many connecting 

 stages, between the three, in other characters. The principal 

 characters separating L. Carestianum from L. ChaiUetii are the 

 plasmodiocarpous habit, the darker, brown or purple walls, and 

 the coarser threads of the capillitium, often with bead-like thick- 

 enings. Var. granuliferum is separated from the typical form by 

 the presence of nodules of lime in the capillitium. The type mate- 

 rial of Didymium granuliferum Phill. has the characteristic lime- 

 nodules in the capillitium, but the spores are abnormally large 

 and irregular, 20-30 fx diam. It is one of those gatherings, often 

 made in other species, where the spores are beyond the usual 

 range, because of somewhat imperfect development. The collec- 

 tion made by Garrett, in Utah (N. Y. B. G. no. 11223), has 

 numerous lime-nodules in the capillitium and brownish spores, 

 paler, on one side, measuring 14-16 ju diam. This is representa- 

 tive var. granuliferum. Several collections of the typical form 

 made by Dr. W. G. Farlow in the mountains of New Hampshire, 

 have the effused, flattened plasmodiocarps showm by the type 

 material of Reticularia Carestiana Rabenh., and the spores are 

 14-15 /x diam., the same as those of the Rabenhorst specimen. 

 Macbride & Martin (Myxomycetes 142. 1934) say that Hark- 

 ness no. 35 from Utah, in the Ellis collection of the New York 

 Botanical Garden, belongs with Lepidoderma granuliferum (Phill.) 

 R. E. Fries, as they prefer to regard L. Carestianum var. granu- 

 liferum. The particular specimen is one of two mentioned by the 

 authors on the following page (143) under L. Carestianum, as 

 representing Amaurochaete minor Sacc. & Ellis. Both specimens 

 have flattened plasmodiocarps, without lime in the capillitium, 

 and spores 15-18 /x diam. The spores are a trifle larger, otherwise 

 the specimens are typical examples of L. Carestianum, agreeing 



