BUREAU OF PLANT INDUSTRY. 193 



THE CAMPHOR INDUSTRY. 



The work on camphor production has been continued during the 

 past year along the lines previously followed. A series of fertilizer 

 tests designed to cover a three-year period has been begun to deter- 

 mine the possibility of increasing the content of camphor in the leaves 

 and twigs of the camphor tree. 



As a result of experiments carried on for several years a satisfac- 

 tory type of camphor condenser has been devised and put into opera- 

 tion. Essentially, this condenser is a copper or zinc chamber cooled 

 by water sprayed upon its exterior. The steam and camphor vapors 

 from the still enter the chamber without contact with the water used 

 for cooling and are condensed upon the chamber walls. This con- 

 denser can be built at a moderate cost and its operation does not re- 

 quire technical supervision. 



POISONOUS-PLANT SURVEYS. 



The identification of plants causing live-stock losses on the west- 

 ern ranges was continued throughout the grazing season. Survevs 

 to determine the areas of greatest danger were made in the Datil, 

 Gila, and Lincoln National Forests. In Arizona and New Mexico an 

 intensive study of " loco " plants was made, since the losses from 

 loco in those States are heavy and widespread. In the mountain or 

 summer ran^e one species. Ox>jtroph lamihertn. causes most of the loco 

 poisoning. In the foothills and on the plains there are many species 

 of Astragalus suspected of being poisonous, but thus far only two are 

 definitely known to be injurious. Extensive collections of material 

 were made for laboratory study. Since there are both annual and 

 perennial species of Astragalus, a critical studv of the seed habits of 

 suspected species was undei-taken, with the object of facilitating the 

 work of eradication. 



Evidence has been accumulated wdiich shows that many plants of 

 the composite family are poisonous. Among the genera known to be 

 poisonous in the Southwest are Baccharis, Chrysothamnus. Dugaldia. 

 Gutierrezia, H3'menoxys, Isocoma, Solidago, and Tetradymia. A 

 systematic study of the characteristics and distribution of these gen- 

 era both in the field and in the principal herbaria of this country has 

 been a feature of the year's work. 



CONGRESSIONAL SEED DISTRIBUTION. 



During the fiscal year 1920 there were distributed on congressional 

 and miscellnuoous requests 10.388J05 packages of vegetable seed and 

 1,503,212 packages of flower seed, or a total of 11,836,917 packages, 

 each containing o packets of different kinds of seed. There were 

 also distributed 14,255 packages of lawn-grass seed and 11.461 

 packages of im])orted narcissus and tulip bulbs. The seeds were 

 purchased on competitive bids, as heretofore. The bulbs were gi-own 

 in the United States bulb-propagating garden, Bellingham, AVash. 

 Each lot of seed purchased was thoroughly tested for purity and 

 viability before acceptance by the department, and tests of each lot 

 of seed were conducted on the department's trial grounds to deter- 

 mine trueness to type. 



