Orobanchaceae, the broomrape family, comprises approximately 150 species in 17 genera. Four genera represented by four species occur in the southeastern U.S. A majority of the genera and about 90% of the species in Orobanchaceae are Old World natives. The family is primarily one of the northern warm and temperate zones. Only about 10% of the species occur in the tropics; only one species reaches the arctic.

Concerns about the effect of pesticides on our environment has stimulated questions about the direction of future research in weed science. Knowledge of crop losses due to weeds would be helpful in guiding research objectives by identifying areas of greatest need. A survey was conducted in 1991 to estimate losses due to weeds in 58 commodities in Canada. Data generated included: percent loss in production, quantity loss in production, and loss of production value (monetary value) for each commodity in each province. The estimated average annual losses caused by weeds in the 58 commodities were $984 million, with losses of $372 million in Eastern Canada and $612 million in Western Canada. In Eastern Canada, approximately 50% of the total loss occurred in hay crops and 33% in field crops, whereas in Western Canada, 84% of the total loss occurred in field crops. Loss of potential production due to weeds for each commodity is shown by province.