The Collaborative International Dictionary
Portulaca \Por`tu*la"ca\, n. [L., purslane.] (Bot.) A genus of polypetalous plants; also, any plant of the genus.
Note: Portulaca oleracea is the common purslane. Portulaca grandiflora is a South American herb, widely cultivated for its showy crimson, scarlet, yellow, or white, ephemeral blossoms.
Purslane \Purs"lane\, n. [OF. porcelaine, pourcelaine (cf. It. porcellana), corrupted fr. L. porcilaca for portulaca.] (Bot.) An annual plant ( Portulaca oleracea), with fleshy, succulent, obovate leaves, sometimes used as a pot herb and for salads, garnishing, and pickling.
Flowering purslane, or Great flowered purslane, the Portulaca grandiflora. See Portulaca.
Purslane tree, a South African shrub ( Portulacaria Afra) with many small opposite fleshy obovate leaves.
Sea purslane, a seashore plant ( Arenaria peploides) with crowded opposite fleshy leaves.
Water purslane, an aquatic plant ( Ludwiqia palustris) but slightly resembling purslane.
Wikipedia
Portulaca oleracea (common purslane, also known as verdolaga, pigweed, little hogweed, red root, pursley) is an annual succulent in the family Portulacaceae, which may reach in height.
Approximately forty cultivars are currently grown.