4 



Preface 



In describing the plants, the writer has dispensed with 

 scientific explanations as far as possible. A few technical terms, 

 however, have been used, and explanations of these may be found 

 in the glossary. Magnifying glasses and other instruments are 

 not necessary, but if used will open up a world of interest in 

 plant mechanics, aesthetics, and biological philosophy. 



The writer wishes to acknowledge indebtedness to Dr. Paul 

 C. Standley of the United States Smithsonian Institution for 

 checking all herbarium material : to Mr. B. C. Tharp of the Uni- 

 versity of Texas and Dr. Paul C. Standley for valuable sug- 

 gestions and for correcting the manuscript; to Supt. Chas. S. 

 Meek now of Toledo, Ohio, and Dr. Jeremiah Rhodes of the San 

 Antonio Public Schools for their constant encouragement and 

 for their generous kindness in granting the writer both freedom 

 and time for research and field work; to Mr. and Mrs. J. P. 

 Classen and Mr. P. J. Classen for the innumerable courtesies 

 extended her while collecting on their ranches; to Mr, Arthur 

 Dean for the map of Bexar County; to Josephine Huppertz 

 Trenkman for drawings used in illustrations; and, to Mr. Roy 

 Quillin, oologist, for his assistance in the field work and for 

 widening the horizon of this work through his unusual powers of 

 observation. 



San Antonio, Texas. 

 9-1-21. 



Ellen D. Schulz. 



