Begonia (The Secret in Vault 13)
From Tardis Wiki, the free Doctor Who reference
Graham O'Brien had a begonia at his house. During one of his return visits home from the travels in the TARDIS, he took this begonia with him. It notified the Thirteenth Doctor that she is needed by the Gardeners. The begonia called Graham "the Giver of Water". (PROSE: The Secret in Vault 13)