
The reasons for marked differences in growth performance of hemiparasites when attached to different hosts are not fully understood. Li et al. study the responses to inorganic solutes in the absence of a host plant of two facultative root hemiparasitic Pedicularis species, P. rex and P. tricolor, that have different host dependency and preference. They find that the two species differ in nutrient requirements and biomass allocation, and conclude that distinct interspecific traits in growth and nutrient requirements could therefore be driving forces for the differential interactions between hemiparasites and their hosts.