blue flowers and lateness of bloom. Suitable for a dry sunny 
situation [nursery]. 
P. atriplicifolia. Afghan, to W. Himal. and Tibet (Jy .-S.). 
PETROPHYTUM, Rosaceae. Prostrate evergreen shrubs that 
are useful for planting in choice positions [5E]. 
P. caespitosum. S. D. to Calif, and N. Mex. (Jy.-Au.). 
P. cinerascens. Wash. 
PETTERIA, Leguminosae. A shrub with yellow flowers similar 
to Cytisus [nursery]. 
P. ramentacea. Istria to Albania. 
PHELLODENDRON, Rutaceae. Cork-tree. Decorative round- 
topped trees with aromatic pinnate foliage and ornamental 
clusters of black berry-like fruits; rapid-growing when young 
[8C, 6D, nursery]. 
P. chinense. C. and W. Japan. 
P. japonicum. C. Japan. 
P. Lavallei. Japan. 
P. piriforme. Orig. unknown. 
PHILADELPHUS, Saxifragaceae. Mock-orange. Many-branched 
shrubs suitable for border or specimen planting. The double 
white-flowered P. virginalis and the pink-centered P. purpureo 
maculatus varieties bloom in great profusion [6J]. 
P. argyrocalyx. N. Mex. 
P. Burkwoodii (P. purpureo-maculatus x virginalis). 
P. caucasicus. Caucasus. 
P. conf us us. Wash. 
P. coronarius. Italy to Cauc. (Jn.). 
P. c. deutziaeflorus. 
P. c. duplex. P. c. pumilus. 
P. c. myrtifolius. P. c. salicifolius. 
P. c. primulaeflorus. P. c. speciosissimus. 
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