5.1" Red Fossil Leaf (Buckthorn) - Montana

This is a 5.1" long, fossil leaf (Rhamnus sp.) from the Fort Union Formation of Montana. Rhamnus is a genus of about 110 accepted species of shrubs or small trees, commonly known as buckthorns in the family Rhamnaceae. Its species range from 1 to 10 meters tall (rarely to 15 m) and are native mainly in east Asia and North America

The color of the rock and the leaves is rather unusual, and different than most of the leaves seen from the Fort Union Formation. They were collected from a locality where a fire in a nearby coal seem "cooked" the rock at sometime in the past. This changed the color and gave it a chalky texture.