Because the “ideal” weed characteristics were derived
from observations of a limited number of weedy species
(Baker 1965), their general applicability to weeds as a
group, and invasive weeds in particular, is not well known.
Crawley et al. (1996) compared life history traits for
British native and alien floras, Williamson and Fitter
(1996) compared life history traits for native plants and
established exotics in the UK, and Daehler (1998)
examined plant family characteristics for global natural
area invaders and agricultural weeds.