At this time of year I am always trying to get the purslane out of my sidewalk cracks.  Now its relative, portulaca or moss rose, is growing out of some of those same cracks and I couldn't be happier.  Purslane is a creeping, succulent plant, with plump green leaves.  It's edible, if you are into such things, and it's vigorous to put it mildly.  I don't eat it, so I pull it out.

Portulaca is also succulent, though its little leaves are not as fat as those of purslane.  The flowers are somewhat poppy-like and come in an array of colors.  Individual flowers only last one day, but the plant produces blooms repeatedly over a long season.  You can encourage the reblooming tendency by deadheading the spent flowers.

The beauty of portulaca, for those of us who experience very dry summers or who grow plants in infrequently watered flower beds and containers, is that it can get along without much water.  Like most succulents, it stores moisture in its leaves. 

Portulaca can be started from seed or from garden center cell packs.  Either way it is easy to grow and a flagrant self-seeder.  (That's how it got into my sidewalk cracks.)  Since it is a low-grower, it is best for the edges of beds and the front of borders.  You can fill pots with single colors or plant a seed mix and enjoy the rainbow.  Either way, it's one less plant to worry about--which will give you more time for the purslane in the sidewalk cracks.