Hypericum septestum
Temporal range:
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Malpighiales
Family: Hypericaceae
Genus: Hypericum
Species:
†H. septestum
Binomial name
†Hypericum septestum
Nikitin

Hypericum septestum is an extinct species of the genus Hypericum that was present during the Oligocene and Miocene epochs. Its holotype is a fossil seed from the Lower Oligocene that was collected in Western Siberia in 1965,[1]: 43  and fossils of the species has also been found in other parts of Russia and in the Czech Republic.[1][2]

Description

The only description of the species is that of the collected fossil seed specimens. The seeds are 0.75–1.4 mm (0.030–0.055 in) long by 0.35–0.6 mm (0.014–0.024 in) wide, and are anatropous and elongated. The seed coat is approximately 0.07 mm thick in the middle of the seed, and is even thinner on its ends. The walls of the testa cells make a pattern of small pits on the surface of the seed, which are 0.04 mm in diameter can be shaped like a square, pentagon, or hexagon. These pits are arranged in nine to twelve rows on each side of the seed. The exotegmen of the seeds consists of a single row of cells which have thick, very porous walls which are rounded or polygonal.[1]: 43 

Taxonomy

While Hypericum septestum has sufficient identifying characteristics to place it within the genus Hypericum, there is not enough surviving detail to assign it to any subdivisions within the genus.[3]

Infraspecifics

  • Hypericum septestum var. sibiricum Nikitin

References

  1. 1 2 3 Arbuzova, O.N. (2005). Takhtajan, A. L. "Hypericum L. Vidy, ustanovlennye po semenam". Iskopaemye Tsvetkovye Rastenija Rossii I Sopredel'nykh Gosudarstv (Fossil Flowering Plants of Russia and Adjacent States) (in Russian). Saint Petersburg. 4: 43–47 – via International Fossil Plant Names Index.
  2. ↑ Ondrej, Zicha. "BioLib: Biological library". www.biolib.cz. Retrieved 2021-02-11.
  3. ↑ Meseguer, Andrea S.; Lobo, Jorge M.; Ree, Richard; Beerling, David J.; Sanmartín, Isabel (13 November 2014). "Integrating Fossils, Phylogenies, and Niche Models into Biogeography to Reveal Ancient Evolutionary History: The Case of Hypericum (Hypericaceae)". Systematic Biology. 64 (2): 215–232. doi:10.1093/sysbio/syu088. ISSN 1076-836X. PMC 4380036. PMID 25398444.
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