Portulaca grandiflora is a succulent flowering plant.It has many common names, including rose moss, eleven o’clock, Mexican rose, moss rose, sun rose, rock rose, and moss-rose purslane.Moss rose will keep blooming all season long with no additional care needed. However, the plants do produce large amounts of seed, so you may see volunteers coming back each year if you plant them once.Grow moss rose in full sun in most soil types.