I like
Lina. It's short, simple, pretty, and reminds me of plants -- I thought that was maybe because of
Linnea but I guess
Lina means palm tree so maybe that's why. I also think it's good as a nickname because a lot of long names end with -lina, but I prefer it on its own as a full name.
I like
Lena too but it's different, it sounds older and more maternal. It also works as a full name or a nickname (
Magdalena,
Helena, etc.)