invasive himalayan balsam impatiens glandulifera bloom flower blossom, expansive species dangerous plants asia neophyte

invasive himalayan impatiens balsam glandulifera bloom ornamental jewelweed flowers kiss mountain blossom expansive leaf species pink purple touching dangerous himalayas plants leaves fruits intruder sachalinensis achenes saw neophyte asia reduces green wild rhizome wildflower collect honey biodiversity eliminates gatecrasher contamination herbicides mechanically flower europe bushes calamity disaster large biomass insect