Though they are technically different broadleaf weeds, both henbit deadnettle and purple deadnettle are in the same family and are often found growing together, taking advantage of similar environments. They are part of the mint family, and may have been brought to the United States as a food before spreading as a weed across lawns.
Purple deadnettle leaves have stalks on the flower stems. Henbit leaves do not. Otherwise the two are similar in appearance. The Leaves are spread out a centimeter or two and circle the stem like a skirt. They are considered pretty enough to be a flower and are sometimes left alone in the gardens, but if your lawn isn’t well maintained it can spread quickly and prevent a green lawn.
As a winter annual, these broadleaf weeds tend to be a bit harder to control. They are easily controlled by pre-emergent herbicides, however, and can be controlled by mulch. As with all broadleaf weeds, dense and healthy turf with deep roots will often choke out both henbit and purple deadnettle.