Hello,
I doubt whether this plant belongs to Arthraxon and that it is a Poaceae at all.
I don't cultivate this plant indeed, and it's obviously not yet available here in Germany.
But there are obviously two little flowers with 3 petals on the first pic in this thread of frozenbarb:
http://www.aquaticplantcentral.com/f...arthraxon.html
Such flowers are characteristic of Commelinaceae (Murdannia, Tradescantia etc.).
Inflorescences of Arthraxon:
http://plants.usda.gov/java/profile?symbol=ARHI3
Has anyone a closeup photo of a flower or inflorescence from emersed "Arthraxon sp. 'Malaysia' "?