Parasitic Fungi of Illinois. 210 



U. hydrangeae, B. & C. 



Hypogenous. Spots small, yellowish, more or less conflu- 

 ent. Sori minute, scattered, few; spores obovate, produced on 

 pedicels, minutely tuberculate, 12-18 by 16-24 /*. 



On Hydrangea arborescens. 



This name is attached, to specimens in the Curtis herbarium, 

 and published in Curtis' Cat. Pits. N. C., p. 122, without des- 

 cription. The specimens from which the description is taken 

 were collected by Mr. F. S. Earle, Cobden, Oct. 13, 1879. 

 There is no evidence of the occurrence of the fungus else- 

 where in the State. 



, TUL. 



Spores one-celled, produced in vertical chains, soon sepa- 

 rating in a powdery mass, sorus without pseudoperidium, but 

 sometimes covered by a thin adherent membrane, often with 

 spermagonia, and with or without paraphyses. 



The term Caeoma has been used with several and very dif- 

 ferent significations. As here limited it does duty, probably 

 temporary, as a genus ,pf so-called species of which teleuto- 

 sporic forms are still unknown. As defined the genus differs 

 from Uredo in the manner of the production of the spores, and 

 from JEcidium in the absence of a peridium. According to 

 some authors the presence of spermagonia is taken as the special 

 characteristic of Cceoma as against Uredo, so that with these 

 writers the forms having spores in chains, but without sperma- 

 gonia, are arranged under the latter, as, for example, the so- 

 called Uredo agrimonice, herein found as Cwoma agrimonia>, 

 Schw. It, however, seems pretty evident that, with or without 

 spermagonia, those forms having spores in chains represent 

 rather the gecidial than the uredo stage, and as some species of 

 jEcidium have no spermagonia, the absence of the latter in 

 Cwoma ought not to be unlocked for. 



Some of the so-called Cceomce- have been identified as the 

 a-cidial forms of Phraymiclium, which see. Compare also Cole- 

 osporium. 



