In the summer of 1998, after the first big burst of "Steel Breath" on the local black market, nineteen-year-old Thomas Jordan decided to combine his need for a lab credit in Chemistry with a hero's need to understand the effects of the mutagenic substance on his city's population. He acquired what low-cost supplies he could manage, including a set of wilting, discarded houseplants from a "going out of business sale". Of the plants in that group, the only one he managed to fully nurse back to health was a stubby daisy-looking thing with yellow and white flower buds on the same trunk.
It was easy for the nineteen-year-old to talk about his day -- and about his secrets, and his missing family, and his other relationships, and his budding career as a superhero -- to the growing plant.
Meanwhile, in a remote campsite in the Catskill mountain range, Rissa started trying to persuade Silverwing to tell her where the site of their shared past was. Every time she asked, he rattled off some excuse ("I need to go water my daisy!") and disappeared for a few hours. The third time, he came back later with a slightly odd-looking potted daisy, which he denied talking to as he walked up to the cave's entrance.
A few days later, while Thomas was away, Rissa heard the "daisy" extract itself from its pot and toddle across the campsite to get at the filtered water storage. Shortly afterward, he started responding to Rissa's greetings and farewells. By the time Thomas moved him into an apartment in Metropolis at the end of September, Bubba had become a fully functional child who happened to be a plant-based sentient person.