Miner's lettuce
Montia perfoliata

Claytonia perfoliata is a ANNUAL growing to 0.2 m (0ft 8in). 
It is not frost tender. It is in leaf 12-Jan It is in flower from May to July. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Flies, self.The plant is self-fertile.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: acid, neutral and basic (alkaline) soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It prefers dry or moist soil.