Hi Ronald,
because this Commelinaceae (likely a Cyanotis sp.) was traded erroneously as Arthraxon spec., I named it Commelinaceae sp. "Arthraxon", admittedly an unfortunate choice of name because Arthraxon is a genus of the Grasses (Poaceae).
I'm curious about the mystery how You hobbyists in NL and Belgium grow it successfully permanently submerged while others failed with the plant. Does it still well also in Your tank?
EDIT
As far as I know, till now these Commelinaceae are known as aquarium plants:
- Commelinaceae sp. "Green" (Floscopa scandens?)
- Commelinaceae sp. "Arthraxon" (Cyanotis sp.?)
- Murdannia keisak
- Murdannia sp. "Red" (submerged leaves reddish, wavy, thin)
- Murdannia sp. "Green" (known to me only from few pics in the www and catalogues, similar to M. sp. "Red"with wavy but green submerged leaves)
In botanical literature one can find hints at quite a number of aquatic and semi-aquatic Commelinaceae. One should look out for such stuff in warm to tropic regions growing in water or flood zones.
Gruß
Heiko