locality by primitive man. It may yet be found on neigh- 
boring mountains, but neither the comparatively thor- 
ough explorations in this general area in the past nor my 
own collecting, directed almost exclusively to Datura, 
have turned it up elsewhere. 
ACKNOWLEDGMENTS 
| would like to acknowledge the help and encourage- 
ment of my major professor, Dr. R. C. Rollins, who 
made available to me the Fernald Fund of Harvard Uni- 
versity for field work in South America. I also owe a 
debt of gratitude to Dr. R. E. Schultes who first sug- 
gested the genus Datura asa research subject and whom I 
had the privilege of accompanying while in South Amer- 
ica. To Dr. Jesis M. Idrobo, Dr. Alvaro Fernandez- 
Pérez and the other members of the Instituto de Ciencias 
Naturales, Bogota, Colombia, I wish to extend my deep- 
est gratitude and appreciation for their kindness and help 
during my stay in their country. 
BIBLIOGRAPHY 
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Dunal, F. 1852. Solanaceae [Datura] in Alphonse de Candolle Pro- 
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Ewan, J. 1944. Taxonomic history of the perennial southwestern 
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Gray, A. 1878. Synoptical Flora of North America, 2, pt. 1: 240. 
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