Pink purslane

Pink purslane

Observation - Pink purslane - UK and Ireland. Description: We saw this plant a couple of days ago and have search the books we have here with out success. There are a number of separate round fleshy stems rising from the ground The leaves are opposite at intervals up stem. From between the top two leaves the

We saw this plant a couple of days ago and have search the books we have here with out success.
There are a number of separate round fleshy stems rising from the ground
The leaves are opposite at intervals up stem.
From between the top two leaves there are one, two or three smaller flower stems
The flowers have five pairs of fused petals that are white with pink streaks.
It was growing on the side of a wet drainage ditch

Any ideas?