IN COLLABORATION WITH
J. J. THORNBER, A.M.
PROFESSOR OF BOTANY IN THE UNIVERSITY OF
ARIZONA, AND BOTANIST OF THE ARIZONA
AGRICULTURAL EXPERIMENT
STATION AT TUCSON
[Illustration]
WITH FIVE HUNDRED ILLUSTRATIONS IN BLACK
AND WHITE, AND FORTY-EIGHT PLATES IN COLOR
DRAWN FROM NATURE BY THE AUTHOR
[Illustration]
C. P. PUTNAM'S SONS
The Knickerbocker Press
NEW YORK AND LONDON
1915
COPYRIGHT, 1915
BY
MARGARET ARMSTRONG