66 



Mycologia 



The first record of a station outside of Mexico. The collec- 

 tions show the characteristic large uredinial sori on the pods, with 

 no other stages. 



19. Ravenelia Caesalpiniae Arth. (Uromyces Caesalpiniae 



Arth.). 

 On Mimosaceae: 



Mimosa ceratonia L., Mayagiiez, March 7, O, II, III, 183; 

 Maricao, March 23, ii, III, 184; Barceloneta, April 6, 

 O, II, iii, 185; Rio Piedras, April 11, O, II, III, 187; 

 Naguabo, April 19, II, 186. 

 This rust, first known and named from the uredinial stage', 

 proved a great surprise when the telia were found among the 

 1 91 5 collections of the Stevens set. The teliospores, instead of 

 being the compound, capitate structures, with cystoid appendages, 

 commonly seen among species of Ravenelia, were single, obovate 

 and pedicillate spores, in no wise differing from those usually 

 placed under Uromyces. The second surprise came in examining 

 the Whetzel-Olive collections. These gave ample telial material, 

 which not only showed what had been seen before, but also many 

 compound spores. Such compound spores are in reality primi- 

 tive teliospore heads, containing 2-8 cells each, those with three 

 cells being most common. The pedicels are adherent the same 

 as the cells. Both cells and pedicels are not merely appressed, 

 but are grown fast together, so that they are made angular, and 

 the cells are squarish above. No indication of cysts can be de- 

 tected. The free, Uromyces-like spores were intermixed with 

 the compound ones. The teliospores germinate readily upon 

 maturity. The telial structure, as well as other characters, now 

 justifies replacing the species under the genus Ravenelia. The 

 specific name proves to be an unfortunate one, as it gives an 

 erroneous impression regarding the affinities of the host. 



20. Prospodium appendiculatum (Wint.) Arth. (Puccinia ap- 



pendiculata Wint.). 

 On Bignoniaceae : 



Stenolobium Stans (L.) D. Don (Tecoma Stans Juss.)j 

 Santurce, April 19, II, III, 374. 



21. Prospodium plagiopus (Mont.) Arth. N. Am. Flora 7: i6f 



1912. 



