EDIT

/**

 * Provides the content for a block of Uses Descriptions for a given taxon.

 *

 * Fetches the list of TaxonDescriptions tagged with the MARKERTYPE_USE

 * and passes them to the theme function theme_cdm_UseDescription().

 *

 * @param string $taxon_uuid

 *   The uuid of the Taxon

 *

 * @return array

 *   A drupal render array

 */

function cdm_block_use_description_content($taxon_uuid) {

  $use_description_content = '';

  if (is_uuid($taxon_uuid )) {

    $markerTypes = array();

    $markerTypes['markerTypes'] = UUID_MARKERTYPE_USE;

    $useDescriptions = cdm_ws_fetch_all(CDM_WS_PORTAL_TAXON . '/' . $taxon_uuid . '/descriptions', $markerTypes);

    if (!empty($useDescriptions)) {

      $use_description_content = theme('cdm_UseDescription', array('description' => $useDescriptions, 'taxonUuid' => $taxon_uuid));

    }

  }

  return markup_to_render_array($use_description_content);

}