Is this.......

[reiverix]

Sorry for the poor picture quality, but is this Ludwigia Glandulosa?

http://www.truescotland.com/glan.jpg

[SnakeIce]

L. Glandulosa has angular wooden stems and even under the best conditions grows only slowly. It falls under the category of plants that can be grown in an aquarium if you really insist and cater to it. Intense lighting, not to acid water, nutritious substrate and water and a temperature below 25C.

it also has alternating leaves which the plant in your photo differs from with paired leaves.

[ergo sum]

How long are the leaves? Are they two different colors on the top and bottom of each leave? Do they reach up toward the top at night and become more prostrate during the day?

[reiverix]

The leaves get about 2 inches long and are the same shade on upper and lower sides. Any leaves in shaded areas are more of a geen color rather than the deep red when under high light. During the night they do reach for the stars.

This is also a fairly fast growing plant and puts out a lot of side shoots when it hits the water surface.

[ergo sum]

Just a guess. Read through this.

http://www.thekrib.com/Plants/Plants/Alternanthera.html