Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

The biology of invasive alien plants in Canada. 3. Amaranthus tuberculatus (Moq.) Sauer var. rudis (Sauer) Costea & Tardif.

Abstract

The annual dioecious weed, Amaranthus tuberculatus var. rudis, was found in 2002 and 2003 infesting soyabean fields in southwestern Ontario, and it was collected in 1992 from waste places in British Columbia, Canada. It is a major weed problem in field crops in the mid-western USA, where it has become increasingly difficult to control during the past 10 years. Morphological differences between A. tuberculatus var. rudis and var. tuberculatus are presented. A review of the biological information published is provided. Plants exhibit high phenotypic plasticity and genetic variability. Emergence is prolonged, growth rapid, and female plants produce a large number of viable seeds that contribute to a persistent seed bank. Amaranthus tuberculatus var. rudis has developed multiple resistance to triazine and acetolactate synthase- and protoporphyrinogen-inhibiting herbicides. Airborne pollen can travel significant distances and A. tuberculatus var. rudis may hybridize with other noxious Amaranthus spp. transferring herbicide resistance or other traits.