Thinking about a color for L, lilac was the first one that came to mind. In Hungarian, our world for purple is "lila." Also, I love the flower; it has an amazingly sweet scent.
(Plants growing on graves revealing injustice about one's death is a very common motif in folklore. This version was collected in Virginia. See the book on the link).
Another lilac episode can be found in the old French fairy tale Blondine. I have a visceral dislike for French fairy tales written in the 18th and 19th centuries - they are literary tales, which makes them too long and too convoluted to tell, and most of them are just too sugary sweet for my taste, with pretty princesses fainting all over the place, and princes crying rivers. Ugh. Anyway, this tale includes Princess Blondine getting lost in the Forest of Lilacs, which is a nice image. You can read the story on the link if you want to.
Lilac also has a Hungarian relation: One specific kind of lilac, Syringa Josikaea, was first discovered in Hungary and named after Countess Rozália Jósika. A lot of sources just call it Josika's Lilac. You can see it in the picture above.
For more lilac, check out Andrew Lang's classic Lilac Fairy Book.
For more Hungarian curiosities, check out my other blog (also participating in A to Z): MopDog - The crazy thing about Hungarians...