Senator Pelek was a female Romulan, she was Elim Garak's contact on Romulus in an Obsidian Order operation to assassinate Proconsul Merrok.
In the ploy she requested the Cardassian embassys gardener - at the time Garak undercover - assist in the growing of Edosian Orchids in her arboretum so that she might fertilise them with White Star of Night seeds to create a toxic flower to use against Merrok (and anyone else she wasn't to fond of).