Surface of gametophyte of Marchantia polymorpha subsp. ruderalis showing alveolae and air pores
<a href="//commons.wikimedia.org/wiki/User:Des_Callaghan" title="User:Des Callaghan">Des_Callaghan</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>