No. 5.] USTILAGINE.E OF CONNECTICUT. 23 



30, 1904; Polygonum sagittatum, Westville, Sept. 2, 1902, 

 Sept. 14, 1903 (Britton), Oct. 4, 1904; Montowese, Sept. 20, 

 1902; Whitneyville, Sept. 2i y 1902; Centreville, Sept. 27, 1902; 

 New Canaan, Oct. 9, 1902 (Britton), Sept. 11, 1903; Yales- 

 ville, Sept. 11, 1903; Andover, Sept. 15, 1903; Cheshire, Oct. 



25, 1903- 



This is another of the common smuts of the state, especially 



on the arrow-leaf Polygonum, and is found in the fall. It is 

 the only purple-spored species of the genus, of which it is the 

 type, however. Fig. $7 shows the smut on Polygonum acre, 

 several of the sori exposing the slender central columella. 



Cintractia Cornu. 



The sori occur on various parts of the host, but most com- 

 monly in the ovaries ; at maturity they form a firmly aggluti- 

 nated, or more rarely a dusty, spore mass, which usually is pro- 

 tected at first by a false membrane of sterile threads or indefi- 

 nite cells. The single spores develop centripetally around a 

 central axis, the outermost wearing off as they ripen ; they are 

 usually of medium to large size, and of a dark reddish black 

 color, often opaque. Figs. 8, 27, 28. 



The species of this genus occur on the Cyperaceas, or occa- 

 sionally on related families. So far 17 species have been de- 

 scribed, 13 occurring in North America, and 4 in Connecticut. 

 None of the species are of economic importance. 



Key to Species of Cintractia. 



I. Sori dusty at maturity, concealed by the glumes. 



A. Spores usually irregular polyhedral C. Cyperi. 



B. Spores usually ovoid to spherical (often with hya- 



line wings) C. Montagnei. 



II. Sori firmly agglutinated at maturity. 



A. Subspherical, in ovaries C. Caricis. 



B. Oblong to linear, surrounding base of pedicles 



C. Junci. 



Cintractia Cyperi Clint. The sori occur in the interior 

 of the spikelets, infecting all of the head, and are hidden by 

 the enveloping glumes until finally the dusty spore mass sheds 



