Plant irrigation device (1) intended to equip a culture vessel (R), such as a pot, said device (1) comprising: - an outer shell (2) intended to be arranged in the culture vessel (R) and being at least partially buried, said envelope (2) delimiting a housing (3) that has an open upper end (4) intended to protrude or emerge from the ground, and a lower end (5) presenting a passage (6 ) on the ground, - a water tank (7) removably disposed in the housing (3) and having a hole (8) around which a first fixing means is arranged, - a diffusion system (10) of water having a second complementary fixing means of the first fixing means, so as to fix the diffusion system (10) to the water tank (7) in communication with the hole (8) of the water tank (7), said diffusion system (10) being arranged to pass through step (6) d and the envelope (2), the envelope (2) has a side wall (12) which, joining the upper (4) and lower (5) ends, presents: - a curved portion (16) having a horizontal section in shape general arc of a circle, characterized in that the envelope has - a portion comprising at least two lateral surfaces (13), which form approximately an angle of 90 ° with respect to each other, said lateral surfaces (13) each presenting of them an edge (15) opposite the angle formed by said surfaces (13), these two edges (15) being joined by the curved portion (16).Dispositivo (1) de riego de plantas destinado a equipar un recipiente de cultivo (R), tal como un tiesto, comprendiendo dicho dispositivo (1): - una envuelta (2) exterior destinada a ser dispuesta en el recipiente de cultivo (R) y a ser por lo menos parcialmente enterrada, delimitando dicha envuelta (2) un alojamiento (3) que presenta un extremo superior (4) abierto destinado a sobresalir o a aflorar de la tierra, y un extremo inferior (5) que presenta un paso (6) en la tierra, - un depósito de agua (7) dispuesto de manera amovible en el alojamiento (3) y que presenta un orificio (8) alrededor del cual está dispuesto un prim
