I think if you made it a little less flattened and grass-like by adding another facet at the side facing the viewer, it would be plausible enough. As you know, though, Alpha has lower levels of scientific plausibility than Beta.

I'd recommend a name other than "Crystal Rupeegrass", though, as it's too close to a Beta lineage. How about Greenswords or Swordgrass?

I've edited the name.

The flattened shape is meant as an adaptation to allow it to grow faster. It wouldn't really work as an organism if it wasn't flattened.

I don't think it's that absurd of a jump, as this sort of adaptation would be a useful one.