Paraguayan purslane (Portulaca amilis) is a non-native landscape weed indigenous to South America. This species is toxic to pets and horses. They are annuals that have succulent leaves and stems. They have small, bright flowers that bloom very quickly.

It was introduced to the southeastern United States and other countries worldwide and can be found in sandy soil in disturbed areas, roadsides, fields, lawns, and gardens.

Source: Wikipedia.