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. {P. grandiflora} is a South American herb, widely cultivated for its showy crimson, scarlet, yellow, or white, ephemeral blossoms.