portulaca(n = noun.plant) - a plant of the genus Portulaca having pink or red or purple or white ephemeral flowers;
is a kind of flower
is a member of genus portulaca
has particulars: portulaca grandiflora, rose moss, sun plant

   A genus of polypetalous plants; also, any plant of the genus. [1913 Webster]
" 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." [1913 Webster]

genus portulaca, portulaca grandiflora, portulaca oleracea