98 MINNESOTA BOTANICAL STUDIES. 



Ascopliora mucedo Tode. 1. c. 1790. 



Mucor stolonifer Ehrb. Sylv. Myc. Berol. 25. 

 B. nigricans Ehrb. 1820, ut supra. 

 Mucor clavatus Lk. Sp. PL vi. 1 : 92. 1824. 

 Mucor amethysteus Behk. Engl. Flor. 5:332. 1832. 

 ? Mucor fuscus (B. and C.) Bekl. and De Toyii.= Ascopliora fiisca 



B. and C. N. A. F. No. «51. 

 ? 3fucor cucurhitarum B. and C. N. A. F. No. 701. 

 ? Mucor beaumontii B. and C. N. A. F. No. 702. 

 The last three are apparently to be placed here. The de- 

 scriptions, particularly of Ascopliora fusca, indicate Ascopliora 

 mucedo and M. beaumontii is said by the authors to differ from 

 31. clavatus principally in the spores. 



Stolons creeping here and there over the substtatum, quickly 

 covering it, at first colorless, then brown; rhizoids more or less 

 branched; sporangiophores rarely single, usually in clusters of 

 3-5 or more on each node, i— 4 mm. high; columella broad hem- 

 ispherical, with the terminal swelling of the sporangiophore 

 forming aclavate cylindrical head reaching almost to the tip of. 

 the sporangium, usually collapsing after the dissolution of the 

 sporangium membrane and remaining a long time covered with 

 spores; spores of various sizes and shapes, irregular globose or 

 oval, with one or two truncated corners, somewhat longer than 

 broad, thick walled, finely striate, averaging 6-17 mikrons. 



On all kinds of decaying organic matter; one of the com- 

 monest of fungi. 



6. ABSIDIA Van TieghExM. Ann. Sc. Nat. vi. 4: 350, 1876. 



Tieghemella Berlese and De Toni 1888, Syl. Fung. VII., 1: 215. 



Fertile mycelium as in Ascopliora; sporangiophores in groups, 

 produced only on the tips of the arched internodes; columella 

 cuticularized, blue-black; sporangia pear-shaped. Zygospores 

 enveloped by unicellular, curved, cuticularized threads, grow- 

 ing out oppositely from the suspensors. 



No species are reported for this country. 



Tribe Thamnidteae. 



Sporangia of two kinds; principal sporangia many spored, 

 with a columella, terminal on the main branches; secondary 

 sporangia (sporangiola) on side branches, few spored, with or 

 without a columella. 



This group is closely related to Mucor, the phenomenon of 

 sporangiola on side branches being occasionally met with in 

 M. mucedo. The typical Thamnidium elegans makes this rela- 



