I checked the GWEN weapon price guide but it didn't stated Spawning Power. Nor did the wiki.
Before you think it's fake :-)
Here is a picture:
http://users.telenet.be/peets/guildwars/Moss_Staff.jpg
Halves Skill recharge of spells (chance: 20%)
Energy + 10
Fire Dmg: 11-22 (Req. 9 Spawning Power)
Armor + 5
Health +59 (while Hexed)
Inscription: "Don't think twince"
Halves casting time of spells (chance: 9%)
Two Handed
P
