1. It is a tetraploid and is grouped in the " Isoetes engelmannii " complex. 2. Waters of the lake host rare species, some of them even extinct like Isoetes lacustris. 3. Its leaves were wider and more succulent than modern spacies of " Isoetes ". 4. Fossilised specimens of " Isoetes beestonii " have been found in rocks dating to the latest Permian. 5. Furthermore, it world s endangered species listed in IUCN Red List such as Isoetes sinensis Palmer inhabit in Dongbaekdongsan wetland. 6. "Isoetes toximontana " is an herb which grows in shallow water, very often emerging above the surface. 7. "Isoetes melanospora " is a small plant growing in mud or shallow water but becoming terrestrial as the ground dries. 8. It is one of several unrelated species of plants from low nutrient lakes known as isoetids, owing to their superficial similarity to Isoetes . 9. Unlike living " Isoetes ", " Tomiostrobus " formed closed cones with sporophylls that were distinctly shouldered and woody. 10. Isoetes engelmannii ", which shares the same common name ), is an aquatic pteridophyte that is widely distributed in the eastern United States.
