Close-up view of orange-colored sunburst lichen (Rusavskia elegans, which replaces Xanthoria elegans) on sandstone. US penny for scale.

---

As these lichens grow slowly, their sizes can be used to assess the relative ages of exposed rock surfaces.

---

Size: 5257px × 3505px
Location: southwestern Montana, USA
Photo credit: © Marli Miller / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: alkaline, beautiful, beauty, biology, bright, circular, close-, colorful, crustose, crusty, dating, elegans, elegant, foliose, fringe, fungus, geochronology, geology, geomorphology, growing, hardy, horizontal, lichen, lichenometry, macro, montana, nature, orange, orange-colored, outcrop, penny, plant, radial, radiating, relative, rock, rusavskia, ruskavskia, sandstone, scale, sky, slow, sunburst, surface, usa, weathering, xanthoria, yellow