A system and device for assisting in planting and growing floating macrophyte-type plant species in uses for the purification of water. The system comprises the use of three devices preferably formed from low-density plastic materials: a plane polygonal floating structure with elements for connecting to other floating structures, provided with at least one inner coupling bar connected to the contour of the floating structure or to another inner bar by a flexible arc； a plane cross-linked structure with elements for anchoring to the floating structure and at least one central circular housing； and a basket or cone consisting of a flexible plastic material and for receiving a macrophyte plant, a root cutting or rhizome with a troncoconical form.
