PHY S A RUM 71 



27. Physarum luteo-album Lister 



1904. Physarum luteo-album List., Jour. Bat., XLIL, p. 130. 

 1911. Physarum luteo-album List, Mycetozoa, 2nd ed., p. 48. 



Sporangia gregarious, subglobose, large, about 1 mm. in diameter, 

 yellow shading into white, orange or olivaceous, smooth or rugulose, 

 stipitate; stipe stout, smooth, .5-1 mm. high, yellow or orange above, 

 white below, cylindric, lime-stuffed; columella large, subglobose or 

 clavate, yellow ; capillitium either of very slender pale yellow, threads, 

 branching at acute angles and anastomosing or of broad, yellow simple 

 or forked strands, persistent after spore-dispersal ; nodules few, small, 

 linear or fusiform; spores purple-brown, spinulose, 10-12 fx. 



This species, originally described from England and northern 

 Europe has more recently been identified in material sent by Professor 

 Sturgis from Colorado. In description the form is well marked ; 

 evinces apparently great variation alike in form, color, and structure. 



The material we have, however, is poor, badly weathered. 



The general plan of structure corresponds very well with Fries' 

 idea of his genus Tilmadoche, although the present species would 

 seem, by very grossness, strangely out of place with the tilmadoches. 

 But the singular, didermoid, evenly branching, threads of the capilli- 

 tium, bearing their slender spindle-shaped burdens of lime are very 

 suggestive; it is a diderma gone wandering into the camp of the 

 physarums if one may judge from Miss Lister's graphic plate. 



The specific name selected for this peculiar form has once before 

 done service, but apparently for something quite dissimilar. Schu- 

 macher, Enum. PL Saell. II., p. 199, has P. luteo-album. Fries thinks 

 he had a perichsna on hand ; at any rate, not a physarum, and makes 

 Schumacher's combination a synonym for Perichaena quercina Fr., 

 which Rostafinski in turn makes synonymous with P. corticalis 

 (Batsch) R. If "once a synonym always a synonym" be esteemed 

 good taxonomic law, this species must one day have another name. 

 The present author, unwilling to change his colleague's preference 

 in this case, nevertheless begs to suggest that such a binomial as P. 

 Itsteri would probably at once make future history of the species less 

 eventful, and honor the memory of England's latest and most dis- 

 tinguished student of the group he loved. 



