query: SELECT (COUNT(DISTINCT ?rank) AS ?count) WHERE {
    ?rank wdt:P105 wd:Q34740. # Q35409 = family; Q34740 = genus; Q7432 = species
    FILTER(NOT EXISTS {
      ?rank schema:description ?itemdesc.
      FILTER(LANG(?itemdesc) = "en") # with missing English description
    })
  }
  LIMIT 1