94 INDEX TO AMERICAN BOTANICAL LITERATURE 
Packard, W. Our vanishing wild flowers. Am. For. 28: 293- 
299. My 1922. [Illust.] 
Payson, E. B. Species of Sisymbrium native to America north 
of Mexico. Univ. Wyoming Publ. Sci. 1: 1-27. 15 Je 1922. 
Describes S. juntperorum sp. nov. 
Payson, E. B. A synoptical revision of the genus Cleomella. 
Univ. Wyoming Publ. Sci. 1: 29-46. 15 Je 1922. 
Includes C. Macbrideana and C. mojavensis, spp. nov. 
Peattie, D. C. Coastal plain element in flora of Great Lakes. 
Rhodora 24: 57-70. f. I-5. 20 Je 1922. 
Pennell, F. W. Scrophulariaceae of the West Gulf States. 
Proc. Acad. Nat. Sci. 73: 459-536. 10922. 
Includes 10 new species, 5 new varieties and 7 new combinations. 
Perry, W. J. A word for the lowly pinon. Jour. For. 20: 521- 
526. My 1922. 
Piper, C. V., & Carrier, L. Carpet grass. U.S. Dept. Agr. 
Farmers’ Bull. 1130: 1-12. f. 1-3. Ap 1922. 
Poole, R. F. Celery mosaic. Phytopathology 12: 151-154. 
bl. 10+ f.1. 6 Je 1922. 
Pritchard, F. J., & Porte, W. S. Isaria rot of tomato fruits. 
Phytopathology 12: 167-172. pl. z2 + f. 1. 29 Je 1922. 
Raines, M. A. Vegetative vigor of the host as a factor in- 
fluencing susceptibility and resistance to certain rust 
diseases of the higher plants. Am. Jour. Bot. 9: 215-238. pl. 
Ei; 22, 23 J@ yoa2, 
Randolph, L. F. Cytology of chlorophyll bis of maize. Bot. 
Gaz. 73: 337-375. pl. 11-16. My 19 
Robbins, W. J. Cultivation of excised root tips and stem tips 
under sterile conditions. Bot. Gaz. 73: 376-390. f. I-4. 
16 My 1922. 
Rosen, H.R. Tilletia texana in Missouri. Ann. Missouri Bot. 
Gard. 8: 357-359. N 1921. 
