Hedeia

Hedeia Temporal range: Early Devonian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Plantae
Division:	incertae sedis
Genus:	†Hedeia Cookson, 1935
Species
H. corymbosa Cookson, 1935[1] (type) H. parvula Jurina, 1969 H. sinica Hao, 1998[2]

Hedeia is a genus of early land plants of uncertain affinity.^[3] It comprises erect axes terminating in corymbose clusters of erect sporangia.^[4]

The type species, H. corymbosa, was first described by Isabel Cookson from a few specimens in fine sandstone from near Alexandra, Victoria, Australia.^[1] She gave no derivation of the generic name. At the time, the locality was regarded as being of Silurian age, but it is now known to be Early Devonian.^[5] It is claimed that an undescribed species, also from Victoria, extends from the Early Devonian back to the Late Silurian.^[5]

H. parvula from Kazakhstan and H. sinica from China are also of Early Devonian age.

It is sometimes suggested that Hedeia and Yarravia are merely different preservations of the same type of plant.^[6]

References

1. Cookson, I. C. (1935). "On Plant-Remains from the Silurian of Victoria, Australia, that Extend and Connect Floras Hitherto Described". Philosophical Transactions of the Royal Society B: Biological Sciences. 225 (521): 127–148. Bibcode:1935RSPTB.225..127C. doi:10.1098/rstb.1935.0009.
2. Hao, S.; Gensel, P. G. (1998). "Some new plant finds from the Posongchong Formation of Yunnan, and consideration of a phytogeographic similarity between South China and Australia during the Early Devonian". Science in China Series D: Earth Sciences. 41 (1): 1–13. Bibcode:1998ScChD..41....1H. doi:10.1007/BF02932414. S2CID 55451586.
3. Kenrick, P.; Crane, P. R. (1997). "The origin and early evolution of plants on land". Nature. 389 (6646): 33. Bibcode:1997Natur.389...33K. doi:10.1038/37918. S2CID 3866183.
4. Chaloner, W. (1972). "Devonian plants from Fair Isle, Scotland". Review of Palaeobotany and Palynology. 14 (1–2): 49–72. doi:10.1016/0034-6667(72)90007-3.
5. Tims, J.D. & Chambers, T.C. (1984), "Rhyniophytina and Trimerophytina from the early land flora of Victoria, Australia", Palaeontology, 27: 265–279
6. See e.g. Hao, Shougang & Gensel, Patricia G. (1995), "A New Genus and Species, Celatheca beckii, from the Siegenian (Early Devonian) of Southeastern Yunnan, China", International Journal of Plant Sciences, 156 (6): 896–909, doi:10.1086/297312, JSTOR 2475120, S2CID 86664097, p. 906.