LEPIDODERMA 141 



KEY TO THE SPECIES OF LEPIDODERMA 



a. Sporangia stipitate, stipe bright orange-brown; rarely 



sessile on an orange-brown hypothallus 1. L. tigrinum 



a. Typically sessile or plasmodiocarpous; rarely stipitate and 



stipe then dark b 



b. Subglobose, pulvinate or short-plasmodiocarpous; spores 



10-13 fj, 2. L. chailletii 



b. Typically plasmodiocarpous; spores usually larger c 



c. Spores 15-18 /j.; capillitium usually vesicular 3. L. granuliferum 



c. Spores 11-15 n\ capillitium not vesicular 4. L. carestianum 



1. Lepidoderma tigrinum (Schrad.) Rost. 



Versuch 13. 1873. 

 PI. X, Figs. 212, 213. 



1797. Didymium tigrinum Schrader, Nov. Gen. Plant. 22. 



1801. Physarum squamulosum Pers., Syn. Meth. Fung. 174. 



1801. Physarum tigrinum Pers., Syn. Meth. Fung. 174. 



1808. Trichia squamulosa Poiret, Lam. Encycl. 8 : 53. 



1808. Trichia tigrina Poiret, Lam. Encycl. 8 : 53. 



1827. Leangium squamulosum Fr., Stirp. Femsj. 83. 



1829. Didymium rufipes Fr., Syst. Myc. 3 : 116. 



1836. Diderma citrinum Berk., Sm. Engl. Flora 5 (2) :310, non Fr. 



1892. Lepidoderma fulvum Mass., Mon. 253. 



Sporangia scattered, rather large, often 1-2 mm. in diameter, 

 hemispherical-depressed, stipitate, umbilicate beneath; peridium shin- 

 ing, olivaceous or purplish, tough, covered more or less abundantly 

 with flat, circular or angular scales; stipe 1-2 mm. tall, stout, furrowed, 

 dark brown, but containing calcareous deposits, tapering upward, and 

 continued within the peridium as a pronounced more or less calcareous 

 columella; hypothallus more or less prominent, yellowish or brownish; 

 capillitium dark, purplish brown, of sparingly branching threads radi- 

 ating from the columella; spores dull purplish brown, minutely spinu- 

 lose, 10-13 fi. Plasmodium orange. 



A singular species, easily recognized by its peculiar, placoid scales, 

 large and firmly embedded in the peridial wall. The internal struc- 

 ture is essentially that of Diderma or Didymium. The species occurs 

 in hilly or mountainous regions, on moss-covered logs. The Plasmodium 

 is yellow, some part of it not infrequently remaining as a venulose 

 hypothallus connecting such sporangia as are near together. 



Meylan records a dwarf phase, form microcarpon, with sporangia 

 only 0.5 mm. in diameter, from the Alps, also a form gracile, with long 

 slender stem, from the Jura Mountains. 



New England to British Columbia and Oregon; rare in the east, 

 common on the Pacific coast; Europe, Japan. 



