Identify the species which is not invasive:

Vallisneria

The correct answer is Option (4) -Vallisneria

Vallisneria is not considered an invasive species. It is an aquatic plant commonly known as eelgrass or tape grass and is not known for aggressively spreading and displacing native species, unlike the other options mentioned (Parthenium, Eichhornia, and Lantana) which are invasive species in certain regions.

When alien species are introduced unintentionally or deliberately for whatever purpose, some of them turn invasive, and cause decline or extinction of indigenous species. Environmental damage caused and threat posed to our native species by invasive weed species like carrot grass (Parthenium), Lantana and water hyacinth (Eicchornia).