178 



affected by a rust (Melampsora medusae). The clover rust (Caeomurus 

 trifoliij was found sparingly on alsike clover and abundantly on red 

 clover, causing some damage to the crop in places. The asparagus rust 

 (Dicaeoma asparagij, so far as it was observed; occurs only upon wild 

 plants, and as this vegetable is not cultivated extensively in the infested 

 region it has little economic importance save as a menace to the occa- 

 sional asparagus beds in the vicinity. The corn rust (Dicaeoma sorghi) 

 was very abundant this season, but is not credited with any serious dam- 

 age. 



The live remaining species are to be regarded as injurious or not ac- 

 cording to the host which they infest. The most important of these is 

 the bean rust (Caeomurus pJiaseoli), which was collected on corn beans 

 and seen abundantly on dwarf beans, which il damaged to a considerable 

 extent. This rust also occurs abundantly on a wild bean ( Straphostyles 

 Ivelvola) Avhich is a serious pest in low river bottoms. The various wild 

 sunflowers as well as the common species (HeliantJms annmts) are often 

 seriously affected by a rust (Dicaeoma helianthi). By the middle of Au- 

 gust the plants of the common sunflower in some sections of Indianapolis 

 were almost defoliated, and such leaves as did remain were rendered 

 unsightly by this rust. Had only that multitude of sunflowers which 

 abound in the river bottoms and about the dumps of the city been in- 

 fected, this rust would deserve a place among the beneficial species. All 

 the wild species of aster are used for ornament, especially in country gar- 

 dens, hence the three aster rusts (Coleosporium solidaginis, Dicaeoma. 

 asteris and 1). caracisasteHs) assume the role of injurious species. This 

 is especially true of the last species, which often sadly disfigures its host. 



A number of species occur upon weeds of greater or less importance 

 and so are to be considered beneficial, inasmuch as they assist in keeping 

 these pests in check. Of these the rust of the wild morning-glory 

 (Dicaeoma corwolvuli) and of the bind weed (Dicaeoma polygoni-con- 

 volvulij are probably the most important, as their hosts are among the 

 worst of the rust-bearing weeds of the region. The rust of the cocklebur 

 and horse weed (Dicaeoma axmtJrn) also deserves mention. The iron weed 

 rust (Ooleosporimn vemonice) is common and often entirely covers the 

 lower surface of the leaves of its host to the serious injury of the latter. 



At the time this collection was made conditions favored the detailed 

 study of the rust flora of a limited area, to wit, section 5, range 4 east. 



