Found some interesting (well, for me at least) photos of Rotala wallichii from a Taiwanese blog site and thought I would like to share this... R. wallichii is a native plant there apparently. According to the description all the photos here are R. wallichii.
http://192.192.42.4/~tbgweb/cgi-bin/top ... 9&show=100
http://192.192.42.4/~tbgweb/cgi-bin/top ... 9&show=100