A plant of the family Portulacaceae having fleshy succulent obovate leaves often grown as a potherb or salad herb; a weed in some areas WordNet 3.0 & Open English WordNet

Purslane is a common name for several mostly unrelated plants with edible leaves and may refer to: Portulacaceae, a family of succulent flowering plants, and especially: Portulaca oleracea, a species of Portulaca eaten as a leaf vegetable, known as summer purslane Portulaca grandiflora, moss rose, or moss-rose purslane Claytonia perfoliata, miner's lettuce or winter purslane Claytonia sibirica, pink purslane Halimione portulacoides, sea purslane Sesuvium portulacastrum, shoreline purslane Honckenya peploides, also called sea purslane Portulacaria afra, purslane tree Wikipedia

Winter purslane, miner's lettuce (Claytonia perfoliata). Wiktionary