56 MADRONO [Vol. 1, 



Joaquin Valley and from San Francisco Bay and its arms south to 

 Orange County, which indicated the distribution of our native wal- 

 nut (Juglans Californica). At that time I knew only two stations in 

 the north for native walnuts, one at Walnut Creek near Mt. Diablo, 

 the other in the lower Sacramento River delta about Walnut Grove, 

 this latter beyond the limits of the colored area on the map referred 

 to above. No locality between Mt. Diablo and the northern bounda- 

 ries of Santa Barbara County was known to me, nor has subsequent 

 exploration or inquiry revealed any station to bridge the long gap 

 between the northern and the southern localities for our native wal- 

 nuts. 



In 1901 Mrs. Ida M. Blochman sent from Santa Maria a collec- 

 tion of fruits of the native walnut. I was much struck by the very 

 small size of the nuts (they were only about % inch in diameter) as 

 compared with the nuts borne by the trees about Walnut Creek, 

 which are over an inch in diameter. These and other differences led 

 the writer to publish the northern tree as a variety (var. Hindsii) 

 of the southern California species. As is frequently the case after 

 publication, information flowed in more rapidly, and seemed to in- 

 dicate that the northern tree should be regarded as a distinct spe- 

 cies. This continued accession of knowledge sometimes discounted 

 this view, sometimes fortified it. Meanwhile Professor Ralph E. 

 Smith, of the Division of Plant Pathology, University of California, 

 had been cultivating both the northern and southern forms in con- 

 nection with his horticultural work on walnuts, and found striking 

 differences in behavior of the seedlings and young trees. The two 

 were planted in rows side by side: the southern form branches low, 

 giving the young tree a pyramidal effect ; the northern form is erect, 

 spindling, not having strong branches or scarcely any. These differ- 

 ences forecast the marked differences in habit between the two 

 forms : the southern form is, strictly speaking, a shrub, gigantic, or 

 even elephantine, but still a shrub in its architecture, with many 

 spreading stems from the base; the northern form is of forest-tree 

 type, even in the open, with erect trunk ten to forty feet high, and 

 bearing a symmetrical and not necessarily very broad crown. These 

 differences thus seem inherent and not ecological. Professor Smith 

 also found in his cultural plots at Whittier that the southern seed- 

 lings were healthy and vigorous, while the northern ones took the 

 "yellows" badly; the southern form produced and held its leaves 

 for a period of 3 to 4 months longer during the year than the north- 

 ern form. 



These and other considerations (see Figs. 27 and 28) seemed to 

 require the specific separation of the northern form, and the writer 

 gave to Professor Smith the name Juglans Hindsii Jepson, which he 

 published in connection with his walnut work in 1909. Such evi- 

 dence as has more recently appeared supports the view then taken. 

 The citation of the two species are therefore as follows : 



