1. 
   Williamsoniaceae
   (from the article `Cycadeoidales`) The Cycadeoidales contained two important families: Williamsoniaceae and Cycadeoidaceae (Bennettitaceae). Williamsonia, the best-known genus of its ...
   Found op http://www.britannica.com/eb/a-z/w/40
   
   
2. 
   Williamsoniaceae
   The Williamsoniaceae are a family within the Bennettitales, an extinct group of seed plants within the Cycadophyta subdivision. Members of this family are believed to have been around two meters tall and with widely serrate leaves along a central stem. Reproductive organs of the Williamsoniaceae ha...
   Found op http://en.wikipedia.org/wiki/Williamsoniaceae
   
   

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