(Definition of a weed. Thank you to my instructor Jayne Giesel!)
Plants that interfere with the growth of desirable plants and are unusually persistent. They damage cropping systems, natural systems, and human activities and as such are undesirable.
– Merril Ross and Carole Lembi, 2009
Weed characteristics:
– Germinates in many environments
– Discontinuous germination and great longevity of seed
– Rapid growth vegetative phase through flowering
– Continuous seed production through growing season
– Very high seed output
– Tolerance and plasticity
– Adaptations for seed dispersal
– Perennial: regeneration from fragments; brittleness
– Ability to compete by special means: rosette, choking growth, allelochemicals