Purslane is a low-growing, spreading plant with reddish stems. Likewise, many varieties of spurge have similar reddish stems and grow to form a mat of foliage close to the ground. Varieties of this sun-loving, annual weed include petty spurge, prostrate spurge, creeping spurge and spotted spurge. Spurge often pops up in mulched flower beds. All surges reproduce by seed, so it's important to pull them before they mature. Unlike purslane, these plants are not edible and will cause gastric illness in humans and animals if consumed.
Miner's lettuce is in the purslane family. It has shiny, dark-green leaves that are either rounded or egg shaped. The leaves and stems are fleshy and thick. Unlike purslane, it prefers moist, shaded areas and it often dries up during the heat of summer. Miner's lettuce is also native to many plant communities, though it can be found in farm fields and disturbed areas as well. As its name implies, miner's lettuce is edible and some varieties are cultivated for salads. Salad lovers should consider limiting their intake of this plant, however, as it can become toxic when it accumulates too many soluble oxalates.
Redmaids is another succulent member of the purslane family native to the U.S. Also called desert rockpurselane, this low-growing plant inhabits grasslands, orchards, agricultural fields and other open, disturbed areas. Redmaids prefers cool weather and languishes in the summer heat. Although it's related to common purslane, it has long, narrow leaves and bright pink flowers with a white center. This plant also is more upright, growing to be about a foot tall. It sometimes spreads over the top of other vegetation and can be a pest in certain cool-weather food crops.
Like purslane, dandelion is a major weed species found in many yards and gardens. It prefers moist soil and full sun, but it's capable of growing almost anywhere once established. The plant's large tap root can reach 10 to 15 feet into the soil, ensuring that it survives dry conditions. More commonly, however, the tap root extends 6 to 18 inches beneath the surface. Dandelion leaves are also edible and the young leaves may be used in salads as long as they haven't been sprayed. Some dedicated dandelion enthusiasts even make wine from the flowers.