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PROCEEDINGS OF THE ACADEMY AND AFFILIATED 



SOCIETIES 



THE BOTANICAL SOCIETY OF WASHINGTON 



The 89th regular meeting of the Botanical Society of Washngton was 

 held on May 6, 1913, at the Cosmos Club with twenty-four members 

 and two guests present. 



The following papers were presented: 



The effect of the recent freeze in California (illustrated) : Dr. David 

 Griffiths. Dr. Griffiths discussed the effect of the January freeze on 

 vegetation of the southwest, with special reference to California. The 

 main regions where tropical and subtropical things are being grown 

 were visited. He showed 40 lantern slides made from negatives taken 

 in February and March, showing injuries to citrus fruits, avocados, 

 cherimoyas, mangoes, carobs, acacias, olives, eucalyptus, etc. 



While the temperatures were unusually low, there are indications 

 that they have been lower in the remote past. That such cold spells 

 of weather are very infrequent is proved by the fact that such natives as 

 Rhus lauriiia, eriogonums in California, and the giant Cereus, scholia, 

 Celtis, Olneya, etc., in southern Arizona are severely injured. Many 

 introduced trees which had attained a diameter of 3 feet were killed 

 outright. Injuries were very severe thruout all of the citrus regions, but 

 even where the temperatures went to 10-17° Fahr. in general thruout 

 a region, an occasional orchard situated upon an abrupt elevation above 

 the general plain escaped with even unfrozen fruit. Because of differ- 

 ences in elevation, air-drainage and exposures, conditions are exceed- 

 ingly varied and present some of the most important problems in con- 

 nection with the relation of climatic conditions to crop development. 

 At no time in the present generation has there been such an oppor- 

 tunity to determine the adaptability of the scores of introduced plants 

 of the Pacific Coast region. Thru some of the various agencies oper- 

 ating in agricultural lines a careful survey should be made the present 

 season to systematize and place on record the results of a condition 

 which, altho of infrequent occurrence, is nevertheless of the utmost 

 scientific and economic import. 



The method of types applied to the nickernut: Mr. H. C. Skeels. Mr. 

 Skeels called attention to the last sentence of division (e) under Canon 

 15 of the American Code of Botanical Nomenclature, which reads as 



379 



