SOME LEADING NUT TREES. 297 



with the paper-shell varieties we may secure hardy varieties 

 with good quality of nut. 



283. The English or Persian Walnut. — In Europe the 

 commercial varieties of Asiatic walnut (Juglans regid) are 

 referred to simply as walnuts. But in the United States 

 they are called English walnuts or Madeira nuts. The 

 varieties from west Europe do not prove hardy in tree, 

 except at a few points in the Middle States, and in many 

 places- where tile tree is hardy they fail to bear nuts profit- 

 ably. Near the seacoast, from New Jersey southward to 

 Georgia, the nut has been profitably cultivated for home 

 use and market for many years. In Florida and the Gulf 

 States it has not been favorably reported, mainly on 

 account of the root-knot. On the Pacific slope the tree is 

 hardy in north California, but as yet varieties have not 

 been found that have borne nuts in a regular and profitable 

 way. In south California, in fertile valleys where water 

 is permanent by seepage from higher irrigated levels, within 

 ten feet of the surface, in Santa Barbara, Los Angeles, and 

 Ventura counties, walnut orchards are proving profitable 

 and the acreage is rapidly increasing. With increased 

 experience, commercial growers now intermingle varieties 

 in orchard planting, even including trees of the native 

 black walnut, to supply pollen. It may prove that lack of 

 pollination is a main cause of failure to perfect fruit in 

 many places where the trees are hardy enough to be used 

 for shade. Luther Burbank, of Santa Eosa, California, is 

 a close observer. He says: "Walnut-trees thrive and 

 grow in Sonoma County, but fail to produce nuts, except 

 a tree here and there. I discovered the reason in 1890 

 and fully confirmed it in 1891. Most of the trees in this 

 section are pistillate, and, with one or two exceptions, they 

 are strictly so. Another reason with some nut trees is that 

 staminate flowers appear too early, or too late to bo of 



