EDIT

  $parent_taxon_nodes = null;

  if($taxon_uuid){

    $parent_taxon_nodes = cdm_ws_taxonomy_pathFromRoot($taxon_uuid);

  }

  $classifications = cdm_ws_fetch_all(CDM_WS_PORTAL_TAXONOMY);

  // find current classification in list

  $classification = null;

  $current_classification_uuid = get_current_classification_uuid();

  foreach ($classifications as $classification){

    if($classification->uuid == $current_classification_uuid){

      break;

  }

  $node_name = '';

  if(count($classifications) > 1 ){

    // need to add the current classification as first label

    $node_name = '<span '. html_class_attribute_ref($classification) .'>'

      . $classification->titleCache . '</span>';

  $rank_limit_uuid = variable_get(TAXONTREE_RANKLIMIT, TAXONTREE_RANKLIMIT_DEFAULT);

  /*

  if($parent_taxon_nodes) {

    // the path to root never contains the classification->root, by asking for

    // the parent node we either get this or the predecessor of the virtual root node.

    $root_parent_taxon_node_dto = cdm_ws_get(CDM_WS_TAXONNODE_PARENT, array($parent_taxon_nodes[0]->uuid));

  } else {

  }*/

  $children_indicator =  '<span class="taxonomic-children-button" data-classification-uuid="'. $current_classification_uuid

    . '" data-rank-limit-uuid="'. $rank_limit_uuid . '" > '

    . font_awesome_icon_markup('fa-chevron-right')

    . ' </span>';

  $items[] = $node_name . $children_indicator;

    foreach ($parent_taxon_nodes as $node){

      $is_first_item = count($items) == 0;

      $node_name = cdm_dataportal_shortname_of($node);

      $path = path_to_taxon($node->taxonUuid);

      $children_indicator = '';

      if($node->taxonomicChildrenCount){

        $children_indicator =  '<span class="taxonomic-children-button" data-cdm-taxon-uuid="'. $node->taxonUuid. '" > '

          . font_awesome_icon_markup('fa-chevron-right')

          . ' </span>';

      }

      $items[] =

        ($is_first_item ? '':  ' ')

        . l($node_name, $path)

        . $children_indicator;

    }