Cultivation, uses, and impact Lythrum salicaria

flowers in lower saxony, germany


as invasive species

naturalised plants growing in cooper marsh conservation area, near cornwall ontario.

the purple loosestrife has been introduced temperate new zealand , north america naturalised , officially listed in controlling agents. infestations result in dramatic disruption in water flow in rivers , canals, , sharp decline in biological diversity native food , cover plant species, notably cattails, crowded out, , life cycles of organisms waterfowl amphibians algae affected. single plant may produce 2.7 million tiny seeds annually. carried wind , water, seeds germinate in moist soils after overwintering. plant can sprout anew pieces of root left in soil or water. once established, loosestrife stands difficult , costly remove mechanical , chemical means.

plants marketed under name european wand loosestrife (l. virgatum) same species despite different name. in cases plants sold sterile, preferable.

in north america, purple loosestrife may distinguished similar native plants (e.g. fireweed chamerion angustifolium, blue vervain verbena hastata, liatris liatris spp., , spiraea (spiraea douglasii) angular stalks square in outline, leaves, in pairs alternate @ right angle , not serrated.

biological control

purple loosestrife provides model of successful biological pest control. research began in 1985 , today plant managed number of insects feed on it. 5 species of beetle use purple loosestrife natural food source , can significant damage plant. beetles used biological control agents include 2 species of leaf beetle: galerucella calmariensis , galerucella pusilla, , 3 species of weevil: hylobius transversovittatus, nanophyes breves, , nanophyes marmoratus. infestations of either of galerucella species extremely effective in wiping out stand of purple loosestrife, defoliating 100% of plants in area. moth ectropis crepuscularia polyphagous , pest species itself, , unsuitable biological control.