Do you know what is Gan (赣 Gàn)? Gan is the abbreviation of Jiangxi (江西 Jiāngxī). Gan or Jiangxihua is really a assortment of Chinese spoken by about 60 million men and women primarily in the Chinese province of Jiangxi, as well as in eastern Hunan (湖南 Húnán) , southeastern Hubei (湖北 Húběi), southwestern Anhui (安徽 Anhuī) and northwestern Fujian (福建 Fújiàn) provinces. It has some intelligibility with Mandarin and Wu (吴 wú). Gan is definitely a substitute title name for Jiangxi province.

Changdu (昌都 Chāngdū), which is spoken in the northwest Jiangxi.
Yiliu (宜浏 Yíliú), which is spoken in the central parts of western Jiangxi.
Jicha (吉茶 Jíchá), which is spoken in central parts of southern Jiangxi.
Fuguang (抚广 Fǔguǎng), which is spoken in central elements of eastern Jiangxi.
Yingyi (鹰弋 Yīngyì), which is spoken in the northeast of Jiangxi.
Datong (大通 Dàtōng), which is spoken in the southeast of Hubei.
Leizi (耒资 Lěizī), which is spoken in the southeast of Hunan.
Dongsui (洞绥 Dòngsuí), which is spoken in the southwest of Hunan.
Huaiyue (怀岳 Huáiyuè),which is spoken inside the southwest of Anhui.

These are the mainly branches of Gan.