Abstract: Device for trimming aristate seeds comprising a vertical spout wherein the seeds to be trimmed travel by gravity counter to a light air flow passing through one of the alveolate plates of a conveyer. In the flow-orientated position, the seeds are housed in one of the alveoli of the plate to be presented in this position to a trimming station comprised for example of a horizontal gas ramp positioned transversally to the direction in which the conveyer is translated.