1988) are not used here for reasons of simplicity (but see the 1981 report, 

 McCarty et al. [1984], and McGregor [1986]). Though the scientific name 

 Euphorbia esula Linnaeus is used for the weed known as "leafy spurge," it must 

 be pointed out that the taxonomy of North American leafy spurge is still 

 controversial among botanists, some of whom consider North American 

 populations to be a complex of species and hybrids (Radcliffe-Smith 1985; 

 Mahlberg et al. 1987; and most recently Crompton et al. 1990). 



Corrections and Updating 



ROBO is a dynamic data base, capable of continual updating with new 

 information. Therefore, readers are encouraged to notify the ARS Biological 

 Control Documentation Center of (1) any errors found in this publication, (2) 

 additional or currently missing information as indicated by question marks, 

 and (3) any changes to scientific names as a result of the publication of de- 

 scriptions of species recorded here as "sp.," or otherwise incomplete names, or 

 as a result of new taxonomic studies. Comments can be addressed to the 

 Biological Control Documentation Center, Bldg. 004, BARC-West, Beltsville, 

 MD 20705. 



References Cited 



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 Thompson, and RW. Carlson, Biosystematic and biological control informa- 

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Coulson, J.R. 1992. Documentation of classical biological control introduc- 

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Coulson, J.R, A. Carrell, and D.L Vincent, compilers. 1988. Releases of 

 beneficial organisms in the United States and Territories — 1981. U.S. De- 

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Crompton, C.W., AE. Stahevitch, and W.A Wojtas. 1990. Morphometric 

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Cronquist, A. 1981. An integrated system of classification of flowering plants. 

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Greathead, D.J. 1986. Parasitoids in classical biological control. /wWaage, 

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Battenfield, S.L., ed. 1983. Proceedings of the National Interdisciplinary 

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 tive State Research Service, U.S. Department of Agriculture, Washington, DC. 



Botschantzev, V. 1974. A synopsis of 5i!z/foi<3; (Chenopodiaceae) from South 

 and South- West Africa. Kew Bulletin 29: 597-6 1 4. 



Bottrell, D.G., C.B. Huffaker, and R.F. Smith. 1976. Information systems 

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Clausen, C.P., ed. 1978. Introduced parasites and predators of arthropod 

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Mahlberg, P.G., D.G. Davis, D.S. Galitz, and G.D. Manners. 1987. Lactifers 

 and the classification o^ Euphorbia: The chemotaxonomy o'i Euphorbia esula L. 

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McCarty, M.K., C.J. Scifres, and L.R Robison. 1984. A descriptive guide for 

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McGregor, RL. 1986. 23. G?rd'««^L., plumeless thistles. /« McGregor, R. 

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