GardenBanter.co.uk - Mayaca or Rotala or what?

I have a plant growing in my tanks that I'd like to ID. I got it at
LFS, unidentified. There was a sprig in my bunch of R. indica that grew
so I went back and bought more. Pic is at
http://eethomp.com/Temp/unknown.html (warning...large download) and the
plant is the fine one in the foreground. I left the pic large so you
can see the detail.

I've been thinking it was Mayaca fluviatilis and then I just found out
about two other plants, Rotala sp. 'Nanjenshan' (likely R. wallichii x
R. rotundifolia) and Mayaca sellowiana Kunth which appear very similar.
So similar, in fact, that Tropica has delcared them the same species
even though the original collections were in Taiwan and South America
respectively. I'm quite sure it's not Rotala wallichii because it has
never shown a tendency to redden, even outdoors.

I was also sent an identical plant labeled Egeria najas from a mail
order plant company when I ordered some for my pond. The plant I have
outdoors has changed its growth habit and grows quite slowly with very
pale, shortened leaves spaced very close together. It shows no tendency
to root and I finally gave up and left it bunched with weights.

The indoor plant branches readily, and also barely roots even in
Flourite. I have been propagating it from cuttings as the bottoms of
the plants eventually turn brown and unattractive. It grows quite tall
and stays healthy growing along the surface under the light but never
starts to grow emersed. If I examine the leaves closely, they have a
slightly greener stripe down the center.

Anybody recognize this plant? Also, any idea how to get it to actually
root and spread?

TIA
--
Elaine T __
http://eethomp.com/fish.html '__
rec.aquaria.* FAQ http://faq.thekrib.com