Any of various succulent plants of the genus Portulaca, especially P. grandiflora of South America, cultivated for its showy colorful flowers that open only in sunlight. Also called moss rose, rose moss.
[Middle English, from Latin portulāca, purslane, from portula, diminutive of porta, gate (from the gatelike covering of the seed capsule); see per-2 in the Appendix of Indo-European roots.]
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