The Rhynie chert sedimentary rock deposit
This Rhynie chert contains fossilized material from vascular plants. The area inside the circle contains bulbous underground stems called corms and root-like structures called rhizoids.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"OpenStax College, Early Plant Life. October 17, 2013."
http://cnx.org/content/m44635/latest/Figure_25_01_04ab.jpg
OpenStax CNX
CC BY 3.0.
