Reproductive biology of leafy spurge (Euphorbia esula L.): breeding systemanalysis

Leafy spurge (Euphorbia esula L.) represents a non-native, invasive weed th at dominates many regions across North America. While many research efforts are aimed at controlling the growth and spread of this plant, relatively l ittle is known about its breeding system. This study provides evidence that leafy spurge is self-compatible, with selfed plants producing roughly half as many seeds as outcrossed plants. Unpollinated flowers failed to set see d and thus preliminary tests for apomixis were negative. However, microscop ic examination of pollinated flowers revealed that pollen tubes did not app ear to enter ovules in either selfed or outcrossed flowers. Therefore, leaf y spurge exhibits structural evidence that suggests pseudogamy may play a r ole in the reproductive strategies of this invasive weed.