An excellent ground cover for taller entities that shades the ground.
"Purslane's mat-like growing habit makes it a good alternative to lawns or other ground covers, particularly for the homeowner focused on edible landscaping. A study conducted by the University of Connecticut concluded that the plant also worked effectively at organically controlling weeds in broccoli patches. By broadcasting purslane seeds before transplanting broccoli seedlings, researchers determined that purslane acted as a "living mulch," comparable to chemical weed control and more expensive mulches, such as black plastic." - Garden Guides
"As a companion plant, purslane provides ground cover to create a humid microclimate for nearby plants, stabilising ground moisture. Its deep roots bring up moisture and nutrients that those plants can use, and some, including corn, will follow purslane roots down through harder soil that they cannot penetrate on their own (ecological facilitation). It is known as a beneficial weed in places that do not already grow it as a crop in its own right." - Wiki