Materials and methods
Study species
Abutilon theophrasti Medicus (Malvaceae) is an annual weedy species, native to China and India. It usually grows to a height of up to 1-1.5 m, and can reach reproductive maturity within 90 d, completing its life cycles in ~5 mo (McConnaughay & Coleman, 1999), with substantial plasticity in allocation, morphology and architecture in response to varying environmental factors (McConnaughay & Bazzaz, 1992). It colonizes relatively nutrient-rich habitats and is typically found in open fields, on roadsides, and in gardens.