THE FUNGI WHICH CAUSE PLANT DISEASE 375 



U. caiyophyllinus (Schr.) Wint.226-229 



I. ^cia on Euphorbia in Europe. 



II. Uredinia sparse, confluent on stems, spores roimd, elliptic 

 or oblong, 40 x 17-28 11, light-brown. 



III. Teliospores globose, irregular or ovoid, apex thickened 23- 

 35 X 15-22 mm., pedicel 4-10 fi. 



II and III on cultivated carnations and several other members 

 of the genus Dianthus. I on Euphorbia gerardiana. It has been 

 known in Europe since 1789 but was not noted in the United States 

 until 1890 when it was found by Taft at Lansing, Mich. It soon 

 invaded the whole country causing great loss. There is large racial 

 difference in host susceptibility. 



The urediniospores germinate readily in water and serve to 

 propagate the fungus. Studies of the effects of toxic substances 

 upon these have been made by Stevens ^'^ and by Stewart.^" The 

 secial stage has recently been recognized by Fischer ''^ as M. 

 euphorbise-gerardianae. 



Less important species are: U. ervi (Wallr.) Plow, an autoecious 

 eu-type on Vicia in Europe; U. erythronii (D. C.) Pass, an opsis- 

 type occasional on cultivated Lilium in Europe. U. ficarise Schw. 

 is on Ficaria; U. pallidus Niess. a lepto-type on Cytisus; U. scil- 

 lanun (Grev.) Wint. a micro-type on Scilla and Muscari. U. jaf- 

 frini Del. is reported on vanilla; ^'^ U. colchici Mas. on Colchinum 

 speciosum in Europe. 



Puccinia Persoon (p. 355) 



O, I, II, as in XJromyces. 



III. Teliospores separate, pedicellate, produced in flat sori, 

 consisting of two superimposed cells each of which is proAdded 

 with a germ pore. The superior cell has its germ pore, as a rule, 

 piercing its apex; in the inferior or lower the germ pore is placed 

 immediately below the septum. 



Mesospores (p. 327) are not rare. They are merely teliospores 

 with the lower cell wanting, and fimction as teliospores. 



Some one thousand two hundred twenty-six species are enumer- 

 ated by Sydow*" presenting great diversity in spore relation, 

 hetercecism and biologic variation. 



