Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
WEN
As described in historical dictionaries
Patronymica Britannica (1860)
SCA WEN. " The name Scawen is local, and signifies a place where slunvan or elder trees grow, and is derived from the Japhetical Greek, cKoftuii, sambachus, ebulus, the elder-tree, who suitable to his name, gives for his arms, ' Argent, a scan-en or elder-tree, Vert.' " Hals, in D. Gilbert's Cornwall, ii. 67.