SRD:Sylvan Scimitar

Sylvan Scimitar: This +3 scimitar, when used outdoors in a temperate climate, grants its wielder the use of the Cleave feat and deals an extra 1d6 points of damage.

Moderate evocation; CL 11th; Craft Magical Arms and Armor, divine power or creator must be a 7th-level druid; Price 47,315gp; Cost 23,657 gp and 5 sp + 1,893 XP.