THE KANSAS UNIVERSITY 

 SCIENCE BULLETIN. 



Vol. VII, No. 15] JUNE, ]913. [vo^.Tvi^n^.^ 



HISTOLOGY OF SALSOLA KALI L. VAR. TENUIFOLIA 

 G. F. W. MEY. 



BY MYRTLE GREENFIELD. 



Plates XXXVIXLII. 



(Contribution from the Botanical Laboratory.) 



(Submitted in parti.al fulfillment of the requirements for the degree of master of arts.) 



Q1ALS0LA KALI L. var. tenuifoUa G. F. W. Mey, commonly 

 |3 known as the Russian thistle, was imported from eastern 

 Europe to South Dakota in 1873 or 1874. It is well 

 adapted to flourish in dry and unfavorable soil, and is widely 

 distributed in such places. The material with which I worked 

 was collected in Logan county, Kansas, during the summer of 

 1911, by F. A. Agrelius and Orville Wilson. 



Salsola kali L. var. teniti folia is not a thistle, as it is com- 

 monly called. It resembles very closely the common tumble- 

 weed, Amaranthus albus, and also another tumbleweed, Cyclo- 

 loma atriplici folium, which belongs to the same family. The 

 young and old plants differ widely. Both have terete leaves, 

 but those of the young plants are long and succulent, while 

 those of the old plant are short. These short leaves on the 

 old plant are in rosette-like bunches. Each leaf, be it ever so 

 short, produces a spine a trifle longer than those produced by 

 the younger leaves. This added number of leaves, each with a 

 spine, gives the plant a very prickly appearance. The photo- 

 graph in figure 36, made by L. M. Peace, shows very clearly 

 the difference between the old and young plants. 



Two characteristics make the plant less troublesome than 

 some of our other weeds. First, it is easily killed ; and second, 



Received for publication April 24, 1913. 



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