It's a flower stem. Val's are sexed & can reproduce by runners or flowers. The stems can grow REALLY fast, up to 1/2" per HOUR. Male plants have short stalked flowers & female have long. That looks like a female.
Eheim Pimp #204.
58 gal planted Oceanic
Red Turquiose Discus, Japonica shrimp, assorted Blue Eyed Rainbows, Tetras, Hatchets, Danios, Rasboras
10 gal low tech planted Celestial Pearl Danio (Celestichthys margaritatus) & Emerald Dwarf Rasbora (Microrasbora erythromicron)