The present study aimed at synthesizing silver nanoparticles (AgNPs) from the aqueous extract of C. nilgirensis and their biopotential using cytotoxicity and phytotoxicity. On mixing the aqueous extract with 1mM AgNO3 solution, the color changes from pale yellow to yellowish brown color. The absorption spectra of yellowish brown nanoparticle showed a plasmon absorption band with a maximum of 3.806 and 1.028 abs in 311 and 440nm, respectively. The Fourier transform infrared spectroscopy (FTIR) spectra confirmed that phenolic compounds have stronger ability to bind with metal, indicating that phenolics could possibly form metal nanoparticles to prevent agglomeration and thereby stabilize the medium. The size of AgNP is found to be in the 45.0-74.0nm range. The Energy-dispersive X-ray (EDX) spectra analysis revealed the presence of a strong Ag peak. The results indicated that C. nilgirensis aqueous extract was found efficient for the synthesis of AgNPs.