Parasitism and haustorium anatomy of Krameria lappacea (Dombey) Burdet & B.B. Simpson (Krameriaceae), an endangered medicinal plant from the Andean deserts

Abstract

Krameria lappacea (Rhatany or Ratanhia, Krameriaceae) is an endangered, overexploited medicinal plant from the semi-deserts of Andean South America, and is destructively harvested from nature. There are published data on parasitism of Krameria from three North American species, but not on K. lappacea, the only economically important species. The present study investigates the presence or absence of hemiparasitism, host plant range and haustorium morphology/anatomy. The study was carried out at two sites in Peru, Department Arequipa, Prov. Arequipa. Hemiparasitism was confirmed, with 106 haustorical connections to 18 host plant species from 17 genera and 12 plant families observed, nearly doubling the number of host plant species known for Krameria (incl. four additional angiosperm families). Root and haustorium architecture and anatomy were found to be similar to the North American species. K. lappacea is a highly generalistic hemiparasite and host distribution and abundance are likely not limiting factors for Krameria recruitment and establishment. Due to its wide range of host plants K. lappacea likely influences the performance of the bulk of perennial species in its habitat and overcollection affects the overall vegetation. Conservation strategies and adequate management should have high priority because of the likely ecological and known economical importance of this species.