Helanthium bolivianum belongs to the "small" runner-forming sword plants, which have been separated from the genus Echinodorus and allocated a genus of their own according to recent relatedness analyses. Most aquarists still know H. bolivianum rather under its "old" name Echinodorus bolivianus.
Opinions vary, which plants really belong to this species. In the widest sense, it comprises several "species" like Echinodorus latifolius, E. angustifolius or E. quadricostatus. In the hobby and in trade, several different plants are named Echinodorus bolivianus in the narrower sense. One of the is probably identical with Echinodorus latifolius (see Helanthium bolivianum "latifolius"), another one, with wider emersed leaves, was known in the hobby decades ago under the name Echinodorus austroamericanus.
To be continued...
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