Tenacious Grass and Lichen

Both grass and lichens are tenacious. This desert rock pile would not seem a very inviting place to grow, but both have thrived. The lichen are barely visible as green patches on the rocks. Lichen is a combination of three plants, a fungus and either a green alga or a cyanobacterium. Lichens are poikilohydric, meaning they can survive on extremely low levels of water content. The grass grows in the spring when the temperature is warm enough and there is still adequate water from the Winter storms. By late Spring, the grass has dried and appears dead, but it will send up new green shoots the following year.