Horace's Chikorita was walking beside Horace at the ancient shrine in Ilex Forest in the Johto region.
Horace's Bayleef is the evolved form of Horace's Chikorita. It evolved sometime between Horace's last encounter with Goh in PM2019 32 and their meeting in the Seafoam Islands in the Kanto region where it was battling a Cloyster which Goh ended up catching.