title: Karkeniaceae
text: # Karkeniaceae
  
  Karkeniaceae is an extinct family in the order Ginkgoales. It contains the single genus Karkenia. It is distinguished by "Ovulate organs consisting of a peduncle and helically arranged, up to about 100 small, orthotropous but incurved ovules; pedicel present; nucellus largely free." Unlike other ginkgoales, the seeds are borne on cone-like aggregations. Ovuluate organs of Karkenia are associated with leaves of the Ginkgoites, Sphenobaiera and Eretmophyllum types. It is known from the Hettangian to Aptian of both Hemispheres.
  
  