Several sources report that Henbit is toxic to horses and some other animals, but we cannot determine exactly what this toxin is. Various tortoise websites list Henbit as being safe for tortoises, but in view of the toxicity reports we feel that it is prudent to err on the side of caution and recommend feeding only sparingly, if at all. Henbit looks similar to Red/Purple Deadnettle, which is edible, so double check that you have the correct identification before feeding any plant.
A feature which will help to distinguish Henbit from Red/Purple Deadnettle is that Henbit has heart-shaped leaves with big scalloped edges that grow along the length of the stem, opposite each other. Towards the top of the stem these leaves have no stalks, but come straight from the stem, and are located just below the small purplish-pink flowers. The leaves on Red/Purple Deadnettle are more triangular in shape and all have little stalks attaching the leaves to the stem. See Deadnettle. (Also see our photo below of the two plants for comparison.)