Didymium. 227 



columella small, spherical, pale ochraccous, internally traversed 

 by irregular strands giving it a cellular appearance, cavities 

 containing crystals of lime; capillitium radiating from the 

 columella to the wall of the sporangium, threads about equal, 

 2 3 p. thick, repeatedly forked and joining laterally, sometimes 

 flexuous and rough in parts with minute granules of lime, 

 varying from colourless, through pale brown to dirty violet; 

 spores globose, very minutely vcrrnculose, brownish-purple, 5 7 /x 

 diameter. 



a. nigripes. Stem blackish. 



/3. rufipes. Stem rufous or yellowish. 



Didymium microcarpon, Host., Mon., p. 157, f. 133, 177 ; Cooke, 

 Myx. Brit., p. 32, f. 133, 177 ; Sacc., Syll., 1316 ; Eaunk., p. 87. 



Exsicc. Ellis, N. Amer. Fung,, 1393 (as Didymium micro- 

 carpon, Fr.), var. nigripes; Ellis, N. Amer. Fung., 412 (as 

 Didymium xanthopus}, 



On twigs, leaves, living mosses, &c. 



Plants 2'5 3 mm. high, lumps of lime on the sporangium 

 in the form of stellate crystals; umbilicus at base of spor- 

 angium sometimes very slight; columella small but rather 

 prominent; the capillitium varies considerably, sometimes 

 copious, anastomosing, various, inclined to be rough here and 

 there with minute granules of lime, or even nodulose ; at other 

 times scanty, colourless, and threads very thin. So far as I 

 have had an opportunity of ascertaining, the pale-stemmed 

 form is confined to living mosses. 



Britain (Kew, King's Cliffe, Carlisle, Shere, Forden, Edin- 

 boro', Glamis, N. B.); Sweden; Denmark; France; United 

 States; Ceylon. 



(Rostafinski's Synonyms.) 



Lycoperdon stipitatum, Retz., Vet. de Handl. (1769). 

 Trichia hemispherica, Trent., p. 228 (1797). 

 Physarum nigripes, Lk., Diss., 1, 27 (1809) ; Ditm., t. 42. 

 Trichia alba, Purt., Midi. Fl., iii., 1113 (1817). 

 Cionium xanthopus, Ditm., t. 43 (1817); Nees, f. 106. 

 Physarum microcarpon, Fr., Gast., p. 23 (1818). 



