Every plant of the planet is a treasure to the human race. But insidious plants show negative impacts on the environment and global diversity. Biotic invasion is one of the five main threats to the bio-diversity and Gujarat is under the intense encroachment of such insidious plants. This study illustrates the status of such invasive plants in Gujarat. Also a study regarding allelopathic interaction of one such insidious plant Lantana camara with Eucalyptus globulus, was carried out. The results show that the reproductive growth of Lantana was totally curbed by decreasing the concentration of phenols and sugars, as both are essential components required for stimulation and initiation of flowering. Allelopathy is a strong and cost effective means of controlling these plants. This method only curbs the growth of plants without totally destroying it. Thus it causes no loss to the bio-diversity.