Brambles of Mordor

Brambles of Mordor were long, hideous, coiled thorns spread across Mordor. They were considered to be as sharp as the daggers of the Orcs of the Black Land.
In TA 3019, Frodo Baggins and Samwise Gamgee encountered these brambles in a valley of the Morgai while traveling through Mordor. As Samwise Gamgee remarked, he hadn't thought that any plants actually grew in Mordor, though had he been told that some do, the brambles were exactly what he would have expected of Mordor.