gt ili te lal 
PREFACE. 
Under direction of the Board of Trustees, the twenty- — 
second annual report of the Missouri Botanical Garden is 
presented to the public. 
The twenty-first report, of 1910, was issued on December 
23, 1910, which marks the date of publication of the scien- 
tific papers that it contains. 
These reports are sent to scientific institutions and journals 
in exchange for publications and specimens desirable for the 
library, herbarium, laboratories or living collections of the 
Garden. So far as is possible, reprints of the botanical 
papers that they contain are sent to botanists occupied with 
a study of the subjects to which they pertain. 
Any of the Garden publications not out of print may be 
purchased, at approximately the cost of publication, from 
Messrs. R. Friedlander & Sohn, Berlin, Germany; W. Wesley 
& Son, London, England; or the undersigned. 
Wiuu1aM TRELEASE. 
Sr. Louis, Mo., December 27, 1911. 
(4) 
