Kheh was a type of stalked grain which was an ingredient in Romulan ale. (TOS - Rihannsu novel: The Romulan Way)
In 2378, Quark used an importer in the Typhon Expanse to purchase kheh from Terix II, with the plan to use the kheh to brew Romulan ale on Deep Space 9. (DS9 novel: Ascendance)
Kheh is grown and harvested in the Rarathik District on Romulus. When Romulan uhlan's began attacking civilians following the assassination of the Imperial Romulan Senate in 2379, Tuvok likened the movement of their truncheons, to the movement of farmers using their scythes to harvest kheh. (TTN novel: Taking Wing)