Image Credit: "Elegant Sunburst Lichen - Xanthoria elegans" by Björn S... © CC BY-SA 2.0

Perfectly suited for the theme of Botany Oddity, the Elegant Sunburst Linchen (Xanthoria elegans) was exposed to the vacuum of space, cosmic rays and high energy radiation while attached to the international Space Station for 18 months![1] On Earth this fungus is found on rocks. With its slow rate of growth, it can be used to approximate the length of time a rock has been exposed to the elements; this method is known to as lichenometry.[2]