A passage from Wild Edible Plants of the California:
California is home to five species of Pennywort, though only three are widespread or regionally abundant. A wetland/riparian (freshwater) plant, look for Pennywort on the edges of slow–moving (or stagnant) bodies of water/marshes.
A passage from Wild Edible Plants of the Texas:
The raw immature leaves are eaten as a salad, used as a garnish, or steamed–sautéed if in need of a cooked green. Raw, the leaves have a refreshing hint–of–celery taste. The older leaves may be a little tough and slightly bitter.