Photograph taken by myself on March 13th, 2009 at the Springs Preserve, Las Vegas, Nevada, United States. Cactus was labeled <i>Mammillaria pseudoperbella</i> (note that the mammies are the inconspicuous blobs around the base of the sign; the large cactus in the middle is most likely <i><a href="//commons.wikimedia.org/wiki/Opuntia_microdasys" title="Opuntia microdasys">Opuntia microdasys</a></i>)
<a href="//commons.wikimedia.org/wiki/User:Prosfilaes" title="User:Prosfilaes">David Starner</a>
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>