Chen Collection, Middle Volume
Radical: Tree (mù)
Sha; Kangxi strokes: 14; Page 543, Entry 20
Pronounced sha.
Shuowen Jiezi (Explaining Simple and Analyzing Compound Characters): Resembles the Japanese cornel (cornus officinalis), growing in the Huainan region.
Tang Yun (Tang Dynasty Rhymes): Resembles the Japanese cornel but has red fruit.
Erya (Approaching Elegance), section on trees: The sha is a type of prickly ash. See the detailed commentary under the entry for the character jiao.
Also, according to Guang Yun (Broad Rhymes), pronounced she. The meaning is the same.
Lei Pian (Categorized Dictionary): Refers to the wedge tree. Another theory suggests it refers to the mountain peach.
Also, according to Ji Yun (Collection of Rhymes), pronounced xue. It means a side strike.