308 InDEX TO AMERICAN BoTANICAL LITERATURE 
Rydberg, P.A. Phytogeographical notes on the Rocky Mountain 
region, X. Grasslands and other open formations of the 
Montane Zone of the Southern Rockies. Bull. Torrey 
Club 48: 315-326. 28 F 1922. 
Saccardo, P. A. Micetes Boreali-Americani. Giorn. Bot. Ital. 
27: 75-88. 1920. 
Sage, H. The royal palm (Oreodoxa regia). Am. For. 28: 85- 
88. F 1922. [Illust.] 
Sax, K., & Gowen, J. W. Productive and unproductive types 
of apple trees. Jour. Hered. 12: 291-300. 20 F 1922. 
[Illust.] 
Schaffner, J. H. Additions to the catalog of Ohio vascular 
plants for 1921. Ohio Jour. Sci. 22: 91-94. Ja 1922. 
Schaffner, J. H. The classification of plants. KIT. Ohio Jour. 
Sci. 22: 129-139. Mr 1922 
Schaffner, J. H. Control of the sexual state in Arisaema tri- 
phyllum and Arisaema Dracontium. Am. Jour. Bot. 
72-78. 20 Mr 1922. 
Schaffner, J. H. Progression of sexual evolution in the plant 
kingdom. Ohio Jour. Sci. 22: 101-113. F 1922. 
Schlechter, R., & Hoehne, F. C. Contribuicdes ao conheci- 
mento das Orquidaceas do Brasil. Anex. Mem. Inst. 
Butantan 1: 9-68. frontis.+pl. 1-14. Mr 1922. 
Includes Fractiunguis and Pseudostelis, gen. nov., 38 new species and 
2 new varietics. 
Schneifer, C. Notes on American willows—XI. Jour. Arnold 
Arbor. 2: 185-204. Ja 1922. 
Setchell, W. A. Aboriginal tobaccos. Am. Anthropologist 23: 
397-414. O-D i921. 
Includes map. 
Severin, H. H. P. Minimum incubation periods of causative 
agent of curly leaf in beet leafhopper and Fels beet. 
Phytopathology 11: 424-429. f. 1-4. 16 F 1 
