358 PROCEEDINGS : POSTON SOCIETY NATURAL HISTORY. 
Ustilago Hieronymi Sehrot. 
Ustilago Hieronymi Sehrot., Hedw., 35 : 213. 1896. 
Ustilago filifera Nort., Trans. Acad. Sci. St. Louis, 7 : 237. 1896. 
Exsiccati: Ustilago filifera Nort., on Bouteloua oligostachya, Griff., West 
Amer. Eungi, 217 a; on Bouteloua oligostachya major , Griff., West Amer. 
Fungi, 217; Ustilago minor Nort., on Bouteloua aristidoides, Griff., West 
Amer. Fungi, 218; on Bouteloua bromoides , Griff., West Amer. Fungi, 
227 ; on Bouteloua eriopoda, Griff., West Amer. Fungi, 219 ; ? on Bouteloua 
polystachya , Griff., West Amer. Fungi, 220; ? on Pappophorum Wrightii, 
Griff., West Amer. Fungi, 224. 
Sori in the leaves and leaf sheaths, usually forming oblong sausage 
shaped pustules, chiefly 1-5 mm. or apparently by terminal coales¬ 
cence more elongated, at first firmly agglutinated but eventually 
with the thin membrane rupturing and the dusty black spore mass 
becoming scattered ; spores dark reddish brown, more or less irregu¬ 
larly polyhedral, occasionally oblong or ovoid, to subspherical, rather 
obscurely ecliinulate, 11-16 /x, in some specimens most elongated 
rarely 20 /x in length. 
Hosts : Bouteloua aristidoides , Ariz., Mex. ; B. breviseta , N. 
Mex.; B. bromoides , Ariz. ; B. eriopoda , Ariz. ; B. Havardii , Ariz.; 
B. oligostachya , Ariz., Colo., Kans. (type U. filifera), Mont. ; ? B. 
polystachya , Ariz.; B. racemosa , Ariz., Kans. (type U. filifera ), 
Utah, Tex. ; ? Pappophorum Wrightii, Ariz.; Triodia pulchella, 
Ariz. 
The writer has received from Hennings a specimen of the type of 
this species on Bouteloua ciliata from Argentine Republic. The 
specimen was very meager. Its spores averaged smaller than those 
of most of the collections examined from this country. This species 
is very closely related to Ustilago Bucliloes and examination of more 
collections of that species may possibly show that they should not be 
kept separate. As now understood Ustilago BucJdoes differs in 
having apparently smooth or very minutely verruculose spores. 
Ustilago Hieronymi, as shown by the specimens collected in this 
country, is an exceedingly variable species. On the one hand it 
nearly runs into Ustilago minor , which differs only in the smaller 
size of the spores. The other extreme is presented by such speci¬ 
mens as issued by Griffiths on Bouteloua oligostachya (nos. 217, 
217a). It is possible that this extreme may deserve varietal or spe¬ 
cific recognition though it is not so sharply marked off as is Ustilago 
