Myriophyllum simulans

Myriophyllum simulans, or filigree Myrio, grows in eastern Australia, mainly in the emersed form in the mud on the edges of various waterbodies or in marshes, where it forms dense lawn-like populations.

It was imported from Australia to Europe in 1983 by P.J. van der Vlugt. First it was named Myriophyllum propinquum. Since then, it has been sold as M. propinquum or "M. propinum" in trade.
In 1986, A.E. Orchard described Myriophyllum simulans as new species in its own right, and the aquarium plant imported from Australia was identified as such. True Myriophyllum propinquum is said to be native only in New Zealand.
M. simulans belongs to a complex of several difficult-to-discern Australian milfoils (e.g. M. jacobsii, M. crispatum, M. variifolium).

The emersed form of Myriophyllum simulans differs clearly from its submersed one: its leaves are not pinnate, have an entire margin and are needle-like to lineal. They grow in whorls on rather thick stems.
The submersed form, however, has finely pinnate leaves, much like many other milfoils. They are of a light green colour, the pinna are hair-thin. The stem is also light green and thinner than that of the emersed form, however, in comparison with other milfoils it is still relatively thick.

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