Abstract: Ivy-leaved speedwell (Veronica hederifolia), an important weed in crop fields throughout Mediterranean countries, was transferred into China in 1980's. This paper dealt with its individual's physiological and ecological characteristics and its population niche. In well aerated soil, the percentage of its seed germination was higher and 10～20% of soil water content was favorable to germination. Soil pHshowed a little effect on germination, but lower temperature promoted it. Ivy leaved speedwell had a similar photosynthesis characteristic with V.persica, and its respiratory intensity was lower than that of other weeds in the same genus. Its actual niche breadth in non crop field habitats in Nanjing suburbs was narrower than that of V.persica and V.didyma. The actual niche overlaps show that V.hederifolia had a similar ecological demand with V.persica and V.didyma.

Key words: Veronica hederifolia, Physiological and ecological characteristics, Niche, fertilization, soil fertility, yellow fluvo-aquic soil