REED: SPECIALIZATION OF PARASITIC FUNGI 371 



H. orygahis, H. strumosus nor H. tuherosus; (3) teleutospores from 

 H. laetiflorus infected H. annuus, H. divaricatus, H. Kellermani, H. 

 laetifloriis, H. mollis, H. occidentalis and H. tomentosits, but not H. 

 grosse-serratus, H. hirsutus, H. orygalus, H. strumosus, nor H. tuberosus. 



About the only conclusion that one can draw is that H. annuus 

 and H. tomentosus are readily infected with teleutospores from a variety 

 of hosts. The evidence for distinct specialized races is not very clear. 



Tranzschel (158) states that he was able to infect Helianthus annuus 

 with teleutospores from Xanthiiim strumarium; the aecidiospores 

 produced on Helianthus annuus infected both H. annuus and Xan- 

 thium strumarium. 



Puccinia Hieracii (Schum.) Mart. Jacky (64) first investigated 

 this rust and found some evidence for specialization, distinguishing 

 one race on Hieracium villosum and suggesting the possibility of several 

 others. Probst (113), more recently, has studied the rust and has 

 come to the conclusion that there are two subspecies, each with several 

 specialized races. He arranges the forms as follows: 



1. Puccinia Piloselloidarum Probst. 



a. Hoppeani on Hieracium hoppeanum. 



b. Peleteriani on Hieracium peleterianum. 



c. Pilosellae (a) on Hieracium pilosella. 



d. Pilosellae ib) on Hieracium pilosella. 



e. Velutini on Hieracium pilosella velutinum. 



f. Auriculae on Hieracium auricula and H. peleterianum. 



g. Floretini on Hieracium florentinum var. obscurum. 



h. Ziziani on Hieracium bauhini, H. florentinum var. alethes, 

 H. pratense and H. zizianum. 



2. Puccinia Hieracii. 



a. Silvatici on Hieracium glaucum, H. humile, H. ocHroleucum, 



H. pictum, H. silvaticum and H. trebevicianum. 



b. Silvatici pleiotrichi on Hieracium silvaticum var. pleiotrichum. 



c. Silvatici gentili on Hieracium folcanum and H. intybaceum. 



d. Schmidtii on Hieracium Schmidtii, H. humile and H. ochro- 



leucum. 



e. Cinerascentis on Hieracium cinerascens and H. ochroleucum. 

 Puccinia Leontodontis Jacky. Probst (112) states that three 



specialized races occur in this rust: 



1. Hispidi on Leontodon hispidus. 



2. Autumnalis on Leontodon autumnalis. 



3. Pyrenaici on Leontodon pyrenaicus. 



Puccinia petroselini (DC.) Lindr. Semadeni (139, 140) dis- 

 tinguishes two specialized races of this rust, one on Aethusa cynapium 

 and the other on Petroselinum sativum. 



