There is not many plants in the Petrified Forest, but there are some here and there. when you do see them the usually have bright colors. Sometimes you see them in purple, below, and sometimes in very bright yellow, like the one above.
invasive species
The Tamarisk trees an invasive species or a "Non-native" Species. Tamarisk was introduced from Eurasia in the early 1900's for its beauty and ability to control bank erosion. Tamarisk has deep roots, up to 100 feet, and can use large quantities of water. So it caused Tamarisk have a bad reputation.