<div class='subscriptions'>
  <%=
    link_to 'Get email alerts for this topic',
      "/email-signup/?topic=#{taxon.base_path}",
      class: 'email-alerts'
  %>
</div>

<div class='subscriptions'>
  <a href="/email-signup/?topic=<%= taxon.base_path %>" class='email-alerts'>
    Get email alerts for this topic
    <span class='visuallyhidden'><%= taxon.title %></span>
  </a>
</div>

Add visually hidden taxon titles to email signup links
Add visually hidden taxon titles to email signup links

Makes the type of email alert a bit more obvious to screenreaders.
