Tulips were an essential part of the gardens of Persia, having been cultivated from the Steppes. As the Seljuks – Oghuz-Turkic leaders originated from the steppes – moved to Persia, and then west, they took tulips with them to Turkey, where many escaped cultivation and became naturalised. Today there are a number of places in Turkey called "Laleli" (‘with tulips’). Tulips first appeared in the decorative arts in Turkey in the thirteenth century and flourished under the Ottomans, in particular in the royal palaces, and was adopted by the Osmans as their symbol. Further species were collected from Persia and the spreading Ottoman Empire saw to it that tulip culture also spread. By the sixteenth century it was a national symbol, hence the designation "Tulip era", by which time they were becoming of economic importance.