To study the impact of vehicular pollution on the road-side
vegetation, four sites in the eastern Uttar Pradesh of India with varying
vehicular density were selected. Index of dominance of five plant species,
Ageratum houstonianum Mill., Argemone mexicana Linn., Rumexdentatus Linn.,
Salvia plebeja R. Br. and Solatium nigrum Linn., were studied atsix intervalstill
250 mperpendicular to the road at all the foursites. An attempthasbeenmade
to correlate the index of dominance of the species with the load of vehicular
pollution. Three species, A. houstonianum, S. plebeja and S. nigrum, showed
positive correlation with respect to the increasing distance from the road,
showing its susceptibility for the pollution whereas A mexicana and
R. dentatus showed positive correlation with the increase in pollution load.
However, a comparison between the two species showed that A. mexicana
was a better bio-indicator of vehicular pollution.