Spot the Difference
Spotted spurge and common purslane are two different plants that are both commonly considered weeds. Spotted spurge is a native summer annual in North America. Common purslane is also a summer annual found in North America.
At first glance, spotted spurge and common purslane could look like the same plant. Both grow in similar environments, infesting lawns or creeping into sidewalk cracks. Both spotted spurge and common purslane have reddish stems with oval leaves. To further complicate the situation, one of the common names for spotted spurge is “milk purslane.”
But that’s about where the similarities end between spotted spurge and common purslane. The leaves of the two plants may be similar in shape and size, but their coloration is different. The “spot” that gives spotted spurge its name is a distinct, dark purplish marking in the middle of each leaf. Purslane, on the other hand, has completely green leaves.
Another difference between the leaves is their succulence. Common purslane is known for having fleshy, “succulent” leaves, whereas spotted spurge has flat leaves. Depending on the stage of the plants you’re observing, their flowers will also help you distinguish them from each other. Spotted spurge has small pink flowers, while common purslane has small yellow flowers.
There are also some similarities between the growth habits of these two plants. Both grow from a taproot and spread low to the ground. They also both have seeds with impressive longevity, though common purslane’s seeds remain viable for a significantly longer time (decades rather than years). One difference between the spread of these two plants is that spotted spurge doesn’t root at the nodes, while common purslane does.
Taxonomically, spotted spurge (Euphorbia maculata) and common purslane (Portulaca oleracea) are not all that similar, either. The two diverge in the rank of order, with spotted spurge in the Rosales order and common purslane in the Caryophyllene order. The lowest rank they share is Magnoliopsida, which is a large class of flowering plants.
One reason it’s important to know the difference between these two plants is that common purslane is known for being edible, while spotted spurge is considered poisonous. The milky white sap that gives spurge the nickname “milk purslane” can cause reactions upon contact or ingestion.
On the other hand, common purslane is considered by some to be a “superfood.” It has a salty, sour taste and is a good source of omega-3 fatty acids. It also contains antioxidants and is a good source of vitamins C, E, and A. Plus, it contains glutathione, melatonin, and betalain. Common purslane is a source of some essential minerals as well, including potassium, magnesium, calcium, phosphorous, and iron.
Keep in mind that common purslane also contains high levels of oxalates. These compounds exist in many plants and don’t make common purslane inedible for most people. However, oxalates can contribute to kidney stones. People at a higher risk of kidney stones are recommended to avoid eating common purslane.
Whether you’re interested in foraging common purslane or just want to identify spotted spurge in your lawn, it’s helpful to know the differences between the two. Look closely to accurately identify which plant you see.