50 THE FLORA OF NEBRASKA. 



[Spinellus rhombosporus (Ehrb.), S. fusiger (Lk.) Van Tiegh., is found on decaying 

 agarics. It may be distinguished by its aerial mycelium which is covered 

 with single or 2-4 verticillate, poiuted, thorn-like branchlets. This 

 species is reported for North America, but has not been met with as yet 

 in this state.] 



[Sijzijgitrs aspergillus (Scopoli), Sporodinia aspergillus (Scop.) Schroeter, is a 

 parasite or saprophyte on fleshy fungi. The sporangiophores are dicho- 

 tomously branched above, and the zygospores are produced in large num- 

 bers on specialized hyphae. It is not yet certainly reported from North 

 America, but is very liable to be found.] 

 Tribe.— Rhizopeae.— Mycelium of two sorts, the vegetative growing on the sub- 

 stratum, and the fertile or aerial mycelium which grows by stolons and 

 upon which the sporangiophores are borne. 



3. ASCOPHORA Tode Fung. Mecklenb. I., 13. 1790. 



Fertile mycelium at first white, then brown or brownish black, growing in all 

 directions by stolons which fasten here and there by rhizoids and at 

 these points produce one or more sporangiophores and other stolons, 

 sporangiophores swelling just below the sporangia; sporangia hemis- 

 pherical, the membrane entirely disappearing; columella hemispherical, 

 forming with the terminal swelling of the sporangiophore, a club-shaped 

 head which collapses and has the appearance of an umbrella; zygospores 

 naked. 



Etymology: Greek acme, sac, and tpopsu, to bear. 



Ascopliora mured o Tode 1. c. 



Mucor stolonifer Ehrb. Sylv. Myc. Berol. 25. 1818. 



Rhizopus nigricans Ehrb. Nov. Act. Acad. Leopol. X., 1, 198. 1820. 



Mucor clavatus Lk. Sp. PL VI., 1, 92. 1821. 



Stolons creeping here and there over the substratum, quickly covering it, at 

 first colorless, then brown; branches 1-3 cm. or longer; rhizoids more or 

 less branched; sporangiophores rarely single, usually in clusters of 3-5 

 or more on each node, }4 to 1 mm. high; sporangia hemispherical, 

 1C 0-350 // wide; columella broad hemispherical, high-arched, with the 

 swelling of the sporangiophore formiug a clavate, cylindrical head reach- 

 ing almost to the tip of the sporangium, usually collapsing after the dis- 

 solution of the sporangium membrane, and remaining a long time covered 

 with spores; spores of various sizes and shapes, irregularly globose, or 

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

 thick walled, finely striate, averaging 6-17 //. 

 On all kinds of decaying organic matter — one of the commonest of fungi. 

 Quickly recognizable by its mode of growth and the peculiar umbrella- 

 like appearance of the collapsed columella. 



Mucor clavatus Lk., Webber's Catalogue No. 129, belongs here. The specimen 

 there referred to is principally A. mucedo, but it seems to have grown 

 over another mould which from the spores is doubtless Mucor mucedo, 

 and the spores of the Ascophora are somewhat larger than usual. PI. 

 XIV, Fig. 4, a, b, c, d. 

 Tribe.— Piloboleae.— Membrane of sporangium of two parts; the upper half cutic- 

 ularized and permanent, the lower thin and quickly dissolving. 



