lyo Journal of Agricultural Research voi. xxn. no. 3 



pycnia took place. When T. angustijoliuvi, T. aqtiilegifolium, T. dioicum, 

 T. minus, T. minus adiantijolium, and T. polycarpum were inoculated 

 usually only pycnia resulted, with an occasional weak development of 

 aecia, while in other cases no infection occurred. Two undetermined 

 species of Thalictrum, as well as T. Delavayi and T. flainmi, when inocu- 

 lated, showed a vigorous development of aecia, increasing in suscepti- 

 bility in the order named. 



(3) Puccinia triticina is apparently limited to species of the genus 

 Thahctrum, no infection being obtained upon species of Aconitum, 

 Actaea, Anemone, Aquilegia, Cimicifuga, Clematis, Delphinium, Echium, 

 Ilepatica, Hydrophyllum, Impatiens, Mertensia, Myosotis, Ornithogalum, 

 Phacelia, Camassia, Ranunculus, or Trollius. 



(4) On account of the morphology and host relationships, Puccinia 

 triticina is considered to be very closely related to P. persistens, P. 

 borealis, P. alternans, P. ohliterata, P. Elymi, and P. Agropyri, but is 

 separable from these rusts by its sharp biologic limitation to wheat. 



(5) Puccinia triticina is considered to be of foreign origin, because 

 wheat, for which it shows close specialization, is an introduced host, and 

 because the most susceptible species of Thalictrum which serve as aecial 

 hosts also are exotic. 



LITERATURE CITED 

 (i) Arthur, Joseph Charles. 



1909-17. CtliTURES OF UREDINEAE IN 1908, I909, 1915, 1916 AND 1917. In 



Mycologia v. i, no. 6, p. 225-256; v. 2, no. 5, p. 213-240; v. 8, no. 3, 

 p. 125-141; V. 9, no. 5, p. 294-312. 

 (2) 



1919. NEW SPECIES OF UREDINEAE — XI. In Bui. Torrey Bot. Club, v. 46, 



no. 4, p. 107-125. 



(3) and Fromme, Fred. Denton. 



1920. DICAEOMA ON POACEAE. In North American Flora, v. 7, pt. 4-5, p. 



269-341. 



(4) Bary, Anton de. 



1866. NEUE UNTERSUCHUNGEN ubER urEdinEEn. In Monatsber. K. Preuss. 

 Akad. Wiss. Berlin, 1866, p. 205-215, i pi. 



(5) BoLLEY, H. L. 



1889. WHEAT rust. Ind. Agr. Exp. Sta. Bui. 26, 19 p., 9 fig. 



(6) Butler, E. J., and Hayman, J. M. 



1906. INDIAN wheat rusts. In Mem. Dept. Agr. India, Bot. Ser., v. i, no. 2, 

 p. 1-52, I fig., 5 pi. (1-4 col.). 



(7) CandollE, a. p. de. 



1815. FLORE FRANfAisE. • • t. 5 (v. 6). Patis. 



(8) Carleton, Mark Alfred. 



1899. CEREAL RUSTS OF THE UNITED STATES. A PHYSIOLOGICAL INVESTIGA- 

 TION. U. S. Dept. Agr. Div. Veg. Physiol, and Path. Bui. 16, 74 p., 

 I fig., 4 col. pi. Bibliography, p. 70-73. 



(9) Cunningham, D. D., and Prain, D. 



1896. A note on INDIAN WHEAT-RUSTS. In Rec. Bot. Survey India, v. i, 

 no. 7, p. 99-124. 



