Chainandra zeugostylus gen. et sp. nov., a mid-Cretaceous amber fossil with sagittate anthers opening widely at maturity

  • George O. Poinar, Jr. Department of Integrative Biology, Oregon State University
  • Kenton L. Chambers Department of Botany and Plant Pathology, Oregon State University

Abstract

A flower preserved in 100 Ma amber from Myanmar is described here as Chainandra zeugostylus, a new genus and species of fossil angiosperms. The anthers in Chainandra are sagittate at the base and have only a short connective. They dehisce by means of a circumferential stomium, the dorsal and ventral sides of each locule forming flaps that become widely separated. The style of Chainandra is columnar and two-branched above the middle, and the fully inferior ovary bears an epigynous nectar disc but lacks well-defined ribs or veins. In Tropidogyne, Lacknociona, and Strombothelya, similar genera described earlier from the same am-ber deposits, the styles are either unbranched or are 3–5-branched to near the base, and the ovary is half-inferior to inferior, its lower portion often being dis-tinctly veined and ribbed. Morphology of the stamens and gynoecium of the three genera suggests that they are early members of the eudotyledons.

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Published
2020-12-07
How to Cite
Poinar, Jr., G. O., & Chambers, K. L. (2020). Chainandra zeugostylus gen. et sp. nov., a mid-Cretaceous amber fossil with sagittate anthers opening widely at maturity. Journal of the Botanical Research Institute of Texas, 14(2), 367-372. https://doi.org/10.17348/jbrit.v14.i2.1015

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