The two most commonly accepted circumscriptions for this order involve either three or five families. Burmanniaceae, Dioscoreaceae and Nartheciaceae are common to both, however the three family circumscription subsumes Thismiaceae into Burmanniaceae s.l. and Taccaceae into Dioscoreaceae s.l. (APG, 2009; eMonocot, 2015; Govaerts et al., 2015 and Trias-Blasi, 2015,). Whereas the five family circumscription keeps the separation (Geeta, 2011 and Stevens, 2015). The five family circumscription is favoured by molecular evidence, which placed Taccaceae closer to Thismiaceae (here Thismieae) than Dioscoreaceae (Merckx et al., 2006, 2009 and 2014), however, their evidence also left Afrothismia isolated. As Merckx et al., admitted better sampling is required to resolve the situation. It appears that choosing to use either the three or five family circumscription is a matter of preference until more complete evidence is available.
It is proposed that WS follows the conservative three family approach in order to maintain consistency with "A genus-level phylogenetic linear sequence of monocots" (Trias-Blasi, 2015), but highlights differences through discussion and notes. However, this taxon page shows the five families for comparison. Andyboorman (talk) 19:28, 10 September 2015 (UTC)