Markah is a type of plant native to Capella IV. Much like Earth tobacco the leaves of the Markah plant are often dried and rolled into cigarillos, however unlike tobacco Markah is not toxic or addictive.
Admiral Leonard James Akaar enjoyed smoking Markah cigarillos as they gave the Capellan Admiral a small taste of home. Akaar knew a freighter Captain who would occasionally bring him boxes of Markah cigarillos, and he would take to smoking them in a small park on the grounds of Starfleet Headquarters. (ST - The Fall novel: The Poisoned Chalice)