FAMILY ENTEROBACTERIACEAE 463 



TRIBE II. ERWINEAE WINSLOW ET AL. 



(Jour. Bact., 5, 1920, 209.) 



Motile rods which normally require organic nitrogen compounds for growth. Pro- 

 duce acid with or without visible gas from a variety of sugars. In some species, the 

 number of carbon compounds attacked is limited and lactose may not be fermented. 

 May or may not liquefy gelatin. May or may not produce nitrites from nitrates. In- 

 vade the tissues of living plants and produce dry necrosis, galls, wilts and soft rots. 

 In the latter case, a pro topee tinase destroys the middle lamellar substance. 



There is a single genus. 



Genus I. Erwinia Winslow et al* 



(Jour. Bact., 2, 1917, 560.) Named for Erwin F. Smith, pioneer American plant 

 pathologist . 



Characters as for the tribe. 



The type species is Erwinia amylovora (Burrill) Winslow et al. 



Key to the species of genus Erwinia. 

 I. **Pathogens which cause dry necrosis, galls or wilts in plants but not a soft rot 

 (Erwinia sensu stricto). 

 A. Gas not produced in sugar media. 



1. Gelatin liquefied. 



a. Starch not hydrolyzed. 



b. Nitrites not produced from nitrates. 



1. Erwinia amylovora. 

 bb. Nitrites produced from nitrates. 



2. Erwinia milletiae. 

 aa. Starch hydrolyzed. 



b. Nitrites produced from nitrates. 



3. Erwinia vitivora. 

 aaa. Action on starch not reported. 



b. Nitrites produced from nitrates. 



4. Erwinia cassavae. 



2. Gelatin not liquefied. 



a. Starch not hydrolyzed. 



b. Nitrites produced from nitrates. 



5. Erwinia salicis. 

 bb. Nitrites not produced from nitrates. 



6. Erwinia tracheiphila. 



* Completely revised by Prof. F. D. Chester, New York, N. Y., December, 1938; 

 further revision by Prof. Walter H. Burkholder, Cornell University, Ithaca, New 

 York, May, 1945. 



** The genus Erwinia as defined here is heterogeneous in nature and is composed 

 of at least two distinct groups. The first group constitutes Erwinia proper and does 

 not produce visible gas from sugars. Waldee (Iowa State Coll. Jour. Sci., 19, 1945, 

 435) in a paper that appeared as this manuscript was ready for the press has sug- 

 gested that the species in this first group be placed in a separate family Erwiniaceae. 



