THE PRESENT study was concerned with the synthesis of AgNPs via application of Haplophyllum tuberculatum crude aqueous extract (HTCAE) as a reducing agent. The resultant extract (HTAgAE) together with the crude one was compared in testing growth and some physiological and molecular parameters of the two recipient species; Triticum aestivum L. as a crop species and Phalaris minor Retz. as weed species. The effect of HTCAE on P. minor revealed significant reduction in growth germination percentage and both radicle and plumule lengths, nevertheless HTAgAE completely inhibited its germination. The HTAgAE at 5% and 10% stimulated the photosynthetic pigments in T. aestivum and reduced them in P. minor at 20% of HTCAE and HTAgAE. The total number of bands, polymorphism percentage and genomic template stability (GTS) % were generally arranged in a descending order by using HTCAE and HTAgAE. This order was reversed with HTAgAE in P. minor at 5% and in T. aestivum at 5% and 20% that reflected antagonistic effect of the nanosilver extract. At 5% HTCAE and 20% HTAgAE, T. aestivum accomplished more genetic stability than P. minor which may support their use as safe bioherbicide.