"In the spring there are tulips in Istanbul."
Translation:İlkbaharda İstanbul'da laleler vardır.
It's just a convention. Proper names that are in their original form receive an apostrophe when you add suffixes to them. It's done out of respect.
So if your name is Tobey, we would write Tobey'den, because it's a proper name. We wouldn't do that with regular words like table, chair or spring, summer.
It is fitting that we learn the word for “tulip”—as opposed to other flowers—considering the plant was first grown in what are now Turkey and Iran. The Dutch, who most of us think “invented” tulips, merely imported the bulbs from Turkey sometime in the 1600’s(?) and marketed them elsewhere in the West.
“Tulip,” it turns out, comes from a Persian word (Persian at that time was the official language of the Uthmanlı court) meaning “turban.” This might have referred to the flower’s resemblance to same, or to the Dutch merchants’ noticing young dandies’ pinning tulip blossoms to their head gear.