46 THE MONTHLY BULLETIN. 



determine the occurrence and abundance of bay fever plants, as well 

 as to procure pollen for testing and for use in treatments for immuni- 

 zation. He considers this well worth while even for use in his own 

 practice. It is highly desirable, however, that the work should be 

 carried on under state or national auspices in order that every district 

 may be thoroughly examined and the results made immediately available. 



The results thus far obtained indicate that certain of our weeds are 

 serious offenders. It. has not yet been possible to examine certain others 

 which are under grave suspicion. It may be said, in general, that most 

 grasses may cause the spring type of hay fever. Johnson grass, ray 

 grass, and a mixture of timothy and red-top all give positive reactions 

 on test. The disturbance caused by grass pollen is usually not so 

 serious as that brought on by pollen of some other plants, more especially 

 certain ones belonging to the composite family. 



Of plants other than grasses, the species thus far investigated include 

 the following:* 



Western Mugworl (Artemisia JieterophyUa) . This weed, so common 

 on ditch and river banks in many parts of the state, is perhaps our 

 worst hay fever plant. Every effort should be made to eradicate it, 

 or at least to hold it in check by mowing, or otherwise, wherever 

 it grows in abundance. 



Western Ragweed (Ambrosia psilostachya) . In the eastern states 

 the ragweed is the most common cause of the disease. Our western 

 species has a larger pollen but its reaction is just as great. 



i locklebur (Xanthium pennsyl/uawicum) gives a positive reaction and 

 is probably important because of its abundance. However, the relatively 

 large size of its pollen grains prevents it from being a more common 

 cause of hay fever. 



False Ragweed (Franseria acanthicarpa) and its close relative, Fran- 

 s, riii h niiifiilia, both give a positive reaction. 



Curly Dock (Bumex crispus) gives a positive but mild reaction. All 

 of the species of dock will probably be found to cause mild cases of 

 hay IVver in some districts. 



Lamb's quarters, White Goosefoot, or Pigweed (Chenopodium 

 album) and "Wormseed (Chenopodium anthelminticum) both give 

 mild reactions. They are probably of little importance. 



Salt-bush (Atriplex). One species (Atriplex bracteosa) gave a very 

 definite reaction in the case of one patient. Since salt-bushes are so 

 abundant in California and produce pollen copiously during the dry 

 season, they will be further investigated with much interest. 



( lalifornia plants which are under suspicion because of their botanical 

 relationships and which will doubtless be found to cause hay fever 

 include the following: 



Sand-bur (Franseria dumosa). 



Poverty Weed, or Western Elder (Iva axillaris). 



Mud-brush (Artemisia spinescens I . 



Russian Thistle (Salsola kali). 



Hymenoelea (Hymenoclea salsola). 



Guatemote, or Mule Fat (Baccharis viminea). 



Spiny clotbur (Kanthium spincsum). 



*For the results of biologic tests here mentioned the author is indebted in some 

 cases to Dr. W. Scheppegrell, President of the American Hay-Fever-Prevention 

 Association, in others to Dr. Grant Selfrldge, of San Francisco. 



