Replacement for Ambulia

Can anyone suggest a plant with a form similar to Limnophila aquatica
(Ambulia), with similar requirements, that is not invasive? My ambulia has
not grown full and fluffy (probably because some floating plants block the
light) but does send runners all over the tank, and pops up where least
wanted. Thanks.

Greg. Tong
San Francisco, CA, USA
gtong at sirius_com

"Every infinity is composed of only two halves."