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.^[1]

Karkeniaceae Temporal range: Hettangian–Aptian PreꞒ Ꞓ O S D C P T J K Pg N
Leaves and seeds of Karkenia henanensis (centre) with Yimaia recurva (top right)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Gymnospermae
Division:	Ginkgophyta
Class:	Ginkgoopsida
Order:	Ginkgoales
Family:	†Karkeniaceae Krassilov, 1972
Genera
Karkenia Archangelsky, 1965

References

1. Zhou, Zhi-Yan (March 2009). "An overview of fossil Ginkgoales". Palaeoworld. 18 (1): 1–22. doi:10.1016/j.palwor.2009.01.001.