Hogwort is a branching annual, densely covered with white or rusty, star-shaped (stellate) hairs. Flowers are densely clustered at the stem tips, with male flowers toward the tip, and female flowers below. Male flowers have 5 tiny white petals and 10–14 anthers. Female flowers have 6–9 calyx lobes, lack petals, and the 3 styles are each split into two twice or thrice (thus, a total of 12–24 lobes). Blooms June–October. Leaves alternate, egg- or lance-shaped, the margins sometimes wavy, at least the middle and lower ones with long petioles. Fruits spherical capsules, densely hairy, about ¼ inch wide, splitting open to release 3 circular or oblong seeds.
Similar species: Seven Croton spp. are known from Missouri. One-seeded croton, or prairie tea (C. monanthogynus), is smaller and less weedy but is found in many of the same habitats. It has only 1 seed per capsule.
Habitat and Conservation
Cattle can become poisoned if they eat hay contaminated with hogwort, but in pastures they tend to avoid eating these bitter, toxic plants. Thus a pasture with lots of hogwort is probably overgrazed.
The dense, stellate hairs of these plants are easily shed when handled and can cause eye irritation.
Author J.K. Rowling did not knowingly name Harry Potter's school of wizardry "Hogwarts" after this plant, but she admitted she must have seen a specimen at the Kew botanical gardens in London at some time, and the name might have stuck in her memory. She recalled it as a lily, however, so she might have seen something very different from this rather lowly pasture weed. And indeed, a completely different plant, giant hogweed (Heracleum mantegazzianum, in the carrot/parsley family and also not a lily), a native to central Asia, was introduced to the United Kingdom in the 1800s as an ornamental. Reaching 20 feet in height, that spectacular plant is an unwanted invasive in Europe. Contact with the sap causes severe blistering and burning of the skin following exposure to sunlight. It, or some other "hogweed" species of Heracleum, might have been the plant Rowling saw. Unfortunately, giant hogweed is currently spreading invasively in the United States, too.
Northern bobwhite and other birds eat the seeds, and dense stands of hogwort and other plants provide good cover for a variety of small animals.
Both hogwort and one-seeded croton are larval food plants for the goatweed butterfly. Goatweed is another common name for hogwort, as is doveweed.