a rust disease that produces conspicuous, perennial, globose galls on the stems of hard pines —note 1. eastern gall rust (also called pine-oak gall rust) is caused by Cronartium quercuum which is closely related to fusiform rust and is heteroecious on jack pine (Pinus banksiana), oak (Quercus), and chinquapin (Castanopsis) hosts —note 2. western gall rust (also called pine-pine gall rust) is caused by Entocronartium harkenssii, which is autoecious on hard pines, including jack pine This definition last updated 10/24/2008