Blade of Grass

The Blade of Grass is a sword, which has a slightly longer reach than the Fiery Greatsword and an average attack speed. It has a green particle effect resembling leaves when swung, and a 25% chance of poisoning its target.

Trivia
The Blade of Grass is likely a reference to Kusanagi (Kusanagi no Tsurugi, lit. Grass-Cutting Sword), a legendary Japanese sword and one of the three Imperial Regalia of Japan, or (much, much more likely) a reference to individual grass leaves which are commonly known as 'blades of grass'.

History
Lame d'herbe Blade of Grass Клинок травы