Fig. 1. On left: Branch showing fruiting of current year, and evidences of previ- 
ous year’s fruiting. Note the white membrane (blister; pushing out 
through swelling in bark. Courtesy of R. G. Pierce, Bureau of Plant 
Industry, U. S. Dep. of .:\.gr. (On right: Sijecimen of lower branch of 
P. flexilis nine years old, three feet high. Has evidently fruited at least 
once in previous years. Nursery B, July 28, 1916. Original. 
