You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <alltransclusions gatcontinue="Delete" />
  </query-continue>
  <query>
    <pages>
      <page ns="10" title="Template:Botanicals" missing="" />
      <page ns="10" title="Template:Citation needed" missing="" />
      <page ns="10" title="Template:Cite book" missing="" />
      <page ns="10" title="Template:Cite patent" missing="" />
      <page ns="10" title="Template:Cite web" missing="" />
      <page ns="10" title="Template:Convert" missing="" />
      <page ns="10" title="Template:Dead link" missing="" />
      <page pageid="645" ns="10" title="Template:Botanical Transclusion Header" />
      <page pageid="241" ns="10" title="Template:Botanics info" />
      <page pageid="711" ns="10" title="Template:ComPort additem/listedit" />
    </pages>
  </query>
</api>