THE KANSAS UNIVERSITY 

 SCIENCE BULLETIN. 



Vol. V, No. 7] OCTOBER, 1909. [^, 



HOLE SSRIBS 

 VOL. XV, No. 7 



KOEBERLINIA SPINOSA Zucc. : 



AN ECOLOGICAL STUDY OF THE ANATOMY OF THE STEM 

 AND SOME OTHER PARTS. 



BY MIRIAM SHELDON. 

 Plates XVII to XXV. 



INTRODUCTION. 



QOME plant forms are peculiar and striking. Those of the 

 ^ desert are particularly individual, many being even gro- 

 tesque in their chance variations. The choice of one of these 

 plants for study was suggested by Professor Stevens, of the 

 Botany Department of the University of Kansas. Accord- 

 ingly, after sectioning and examining about fifty or sixty 

 plants, I selected and studied three more carefully. Of these 

 the subject of this sketch is perhaps the most interesting. 



The material for this study was obtained in the summer of 

 1908. In July of that year collections of about sixty or seventy 

 different species were made by Mr. L. M. Peace, of the Uni- 

 versity of Kansas laboratories. These were taken from the 

 region around about Tucson, Ariz., representatives of some 

 species being taken from several habitats, as from mesa, 

 wash, irrigating ditch or hill top. As the short summer 

 season of rains had just begun some of the plants were ob- 

 tainable before the leaves had appeared. Specimens were, of 

 course, also taken after the leaves came out. The jars with 

 their preserving fluid (two per cent formalin) were taken into 

 the field, and the plants put into these as soon as collected. In 

 many instances the whole plant was secured, one jar containing 

 the root, stem, leaves and flower or fruit of the same plant. It 

 will be seen that this collection is particularly valuable because 



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