422 PROCEEDINGS: BOTANICAL SOCIETY 



Regular Program 



Mr. IvAR TiDESTROM read an illustrated paper on the Flora of Utah 

 and Nevada. He said that no region within the limits of the tlnited 

 States is marked by a more diversified flora than that of the Great 

 Basin. Its plains and desert areas are found at an elevation of 600 

 to 1,500 meters above sea-level while its numerous mountain ranges 

 rise in some instances above 3,900 meters altitude. Within this region 

 we find the northern boundary between the flora of Mexico and that 

 of western North America. This line coincides with the upper limit 

 of Covillea glutinosa, Yucca mohavensis and Cleistoyucca arborescens. 



In the West-American Dominion there are several characteristic 

 belts, the lowest of which is dominated by Artejntsia tridentata. The 

 latter has a wide range as it ascends to 3,000 meters elevation or more 

 on exposed slopes. At 1,500 meters above sea-level, the pinon and 

 its associated Juniperus species becomes the dominant element. Above 

 the pinon, especially on the plateau, Pinus scopidonim rules. This 

 species forms forests in New Mexico and Arizona. Adjoining the 

 pinon and ascending higher (2,700 meters or more) the aspen becomes 

 the dominant element. In central Nevada Cercocarpus ledifolius 

 replaces to a large extent the aspen. At 2,700 meters above sea- 

 level Picea engelmanni and associated Abies species forms the spruce- 

 belt. The belt is succeeded by the alpine flora of which many species 

 are circumpolar. 



Dr. P. J. S. Cr-\mer, Chief of the Division of Plant Breeding, De- 

 partment of Agriculture, Java, spoke on Problems in tropical plant 

 breeding. He confined his remarks principally to breeding with the 

 rubber plant Hevea brasiliensis, giving a brief description of the cultural 

 methods employed. He stated that good strains may be developed 

 from seedlings but more success may be expected from budded plants 

 if buds are used from the highest yielders. Budded rubber plants 

 sometimes show a tendency to low branching, but proper selection of 

 buds will prevent this. If the top of the branch is used as a scion the 

 graft will not develop a stem, but if the top of the stem or leader is 

 used, a normal tree is obtained. 



Chas. E. Chambliss, Recording Secretary. 



