Stangeriaceae

Stangeriaceae
Stangeria eriopus in coastal lowland forest,
South Africa
Scientific classification
Kingdom:Plantae
Division:Cycadophyta
Class:Cycadopsida
Order:Cycadales
Suborder:Zamiineae
Family:Stangeriaceae
Schimp. & Schenk
Genera

Bowenia
Stangeria

Stangeriaceae is the smallest family of cycads, both in number of living and fossil species. The family contains only two living genera, Stangeria and Bowenia, though the latter genus has been recommended for placement in a separate family by itself.

The family is recognized as having vascularized stipules, and by lacking cataphylls, or producing them irregularly. These unusual characters led to the original description of Stangeria as a fern, and it was only when seeds were later produced on the plant that its true affinities were realized.[1]

Though today the family occurs only in South Africa and Queensland, Australia, fossils are known from Jurassic sediments in Argentina and the British Isles.[2] Recent cladistic studies suggest that the fossil taxon Mesodescolea may also have affinities with the Stangeriaceae. This highly lobed fossil leaf from the Lower Cretaceous has only been found in Argentina. Another fossil from the Lower Cretaceous of Argentina, Eobowenia incrassata, has been recently suggested as the oldest relative of Bowenia.[3]

References

  1. ↑ "The Cycad Pages: Stangeria eriopus", Royal Botanic Gardens Sydney website
  2. ↑ Fossil record of the Cycads
  3. ↑ Coiro,M.; Pott,C. (2017). "Eobowenia gen. nov. from the Early Cretaceous of Patagonia: indication for an early divergence of Bowenia?". BMC Evolutionary Biology. 17 (1): 97. doi:10.1186/s12862-017-0943-x.
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