PREFACE 



The author is very grateful to the following contributors : Roxana Stinchfield 

 Ferris for the family Euphorbiaceae, except for the genus Euphorbia whicii was con- 

 tributed by Louis Cutter Wheeler, and for the text of Hackelia in the Boraginaceae ; 

 Ira Loren Wiggins for the families Malvaceae, Cactaceae, except for the genus 

 Opuntia which he contributed jointly with Carl Brandt Wolf, and the Solanaceae; 

 George Neville Jones for the family Hypericaceae ; Philip Alexander Munz for the 

 family Onagraceae; Mildred Esther Mathias and Lincoln Constance for the family 

 Umbelliferae ; Rimo Bacigalupi for the family Garryaceae ; Herbert Louis Mason for 

 the family Polemoniaceae, except for the genus P olemonium which was contributed 

 by John Eraser Davidson and for the genus Gilia which was contributed jointly by 

 Herbert Louis Mason and Alva Day Grant ; Lincoln Constance for the family Hydro- 

 phyllaceae ; and Erancis Whittier Pennell for the family Scrophulariaceae, except for 

 the genera Orthocarpus and Penstemon which were written by David Daniels Keck. 

 The text of the remaining famihes was written by the author. Ira Loren Wiggins 

 has given much assistance in solving the nomenclatorial and taxonomic problems. 

 Roxana S. Eerris has selected the material for the original illustrations and, together 

 with Sylvia Vincent and Barbara Law, has done the necessary editorial work of 

 checking references and reading manuscript and proof. 



As in Volume I the illustrations are original except those which were used from 

 Britton and Brown's Illustrated Flora of the Northern United States and Canada. 

 The use of these illustrations is gratefully acknowledged to the New York Botanical 

 Garden. The original drawings are, for the most part, the work of Jeanne Russell 

 Janish. The drawings for the Onagraceae and Polemoniaceae were, in part, made at 

 Pomona College and the University of California, respectively. A number of drawings 

 scattered throughout the various plant families have been made by William S. Atkin- 

 son, Alice Baldwin Addicott, Louise Nash, and Lawrence Beane. 



L.R.A. 



Stanford University 



