Ral Benem aka Chlorophyll Kid hailed from the planet Mardru, and was a member of the Legion of Substitute Heroes. When he was young he accidentally fell into a tank of hydroponic serum which gave him the power to stimulate plant growth. He could grow seeds into full grown plants in a second. Chlorophyll Kid could also direct the growth of vines so that, for example, they wrap around someone to capture them.
Chlorophyll Kid possessed an extensive knowledge of botany. He carried a variety of seeds in his costume for various uses. Like many young metahumans of the era he tried out for the Legion of Super-Heroes, but was rejected when the Legion decided that his power would not be useful on missions.
Along with four other refused applicants, Polar Boy, Night Girl, Stone Boy and Fire Lad, he helped form the Legion of Substitute Heroes, aka 'the Subs'. This team repeatedly proved their effectiveness as heroes - frequently saving the day where the Legion of Super-Heroes had failed. In 'gratitude', the Legion condescendingly permitted them to continue to function, and accepted them as 'Legion Reservists'.
