Family 1. USTILAGINACEAE 



By George Perkins Ci^inton 



Sori usually forming exposed dusty or agglutinated spore-masses. Germi- 

 nation by means of a septate promycelium which gives rise to terminal and 

 lateral sporidia (capable of yeast-like multiplication in nutrient solutions) or 

 else to infection-threads. 



Spores single. 



Sori dusty at maturity. 



Without definite false membrane. 1 Ustilago 



With false membrane of definite fungous cells. 2. Sphacelotheca 



Son agglutinated at maturity. 



Firmly agglutinated into conspicuous tubercular nodules. 3. Melanopsichium 



Developed around a central columella (rarely dusty). 4. Cintractia 



Spores chiefly in pairs. 



Sori agglutinated (on leaves). 5. Schizonella. 



Son dusty (inside peduncles). 6. Mykosyrinx. 



Spores in balls. 



Sori dusty or granular. 



Spore-balls often evanescent ; spores olive-brown or black-brown. 7. Sorosporium. 



Spore-balls rather permanent; spores yellowish or reddish, with 



markings only on free surface. 8. Thecaphora. 



Spore -balls quite permanent ; spores adhering by folds or thickenings 



of outer coat. 

 Sori agglutinated. 



Spore-balls (variable) composed of thick-walled spores. 9. Tolyposporella. 



Spore-balls with peripheral spores and central sterile cells. li. Testicularia. 



10. TOLYPOSPORIUM. 



1. USTILAGO (Pers.) Roussel/ Fl. Calvados ed. 2. 47. 1806. 



Necrosis Paulet, Traits Champ. 1 : 54S ; hyponym. 1793. 



Uredo § Ustilago Pers. Syn. Fung. 224. 1801. 



Usiilagidium Herzb. in Zopf, Beitr. Phys. Morph. Org. 5 : 7. 1895. 



Sori on various parts of the hosts, at maturity forming dusty, usually dark-colored 

 spore-masses ; spores single, produced irregularly in the fertile mycelial threads which 

 early entirely disappear through gelatinization, small to medium in size ; germination by 

 means of a septate promycelium producing only infection -threads or with sporidia formed 

 terminally and laterally near the septa ; sporidia in water usually germinating into infection- 

 threads but in nutrient solutions multiplying indefinitely, yeast fashion. 



Type, Uredo segetum Pers. 



A. Spores reddish-, olive-, or black-brown. 



1. Spores perfectly smooth (see also nos. 3, 19, 25, 33). 

 Spores small, 4-10 jLt in length. 

 Sori around the internodes. 



.Sori with false membrane of fungous threads. 1. V . tninima. 



Sori without evident false membrane. 2. U. hypodyies. 



Sori envolving entire inflorescence. 20. U. Panici-proliferi. 



Sori in individual spikelets. 



Spores lighter- colored on one side. 



Sori small, about 1 mm. in length. 5. U. mexicana. 



Sori 6-10 mm. in length. 



Hosts: v4z/fwa; spore-mass brown-black. 7. (J.levis. 



Hosts : Hordeum ; spore-mass purple-black. 6. U. Hordei. 



ij. Bauhin, Hist. PI. 2 : 418, in 1651, is really the founder of Ustilago. Fries or Per- 

 soon is ordinarily cited as the authority for the genus. Fries used Ustilago as a genus in 

 his Syst. Myc. 3 : 517, in 1832, with U. grandisas the first species. Persoonused Ustilago 

 as a subgenus under Uredo with Uredo segetum as the first species, having five varieties of 

 which a U. Hordei is first, and this may be taken as the actual type now that U. segetum 

 has been broken up into several species. Roussel merely adopted Ustilago from Persoon, 

 but raised it to full generic rank, giving three of Persoon 's four species, of which U. segetmn 

 is one. Paulet's name, Necrosis, cannot be regarded as a true generic name, but was used 

 more as a descriptive term. 



Volume 7, Part 1, 1906] 3 



