Dittrichia graveolens aka Camphor Inula

Dittrichia graveolens, or stinkwort, belongs to the daisy family. It is an annual: it lives for one year. Its native range spans the Mediterranean to the western Himalaya. It now grows beyond that range, in California and Australia. Records place it in several eastern US states too. People also call it stinking fleabane and camphor inula. Its old names include Inula graveolens and Erigeron graveolens.

The plant grows upright, with branches that form a cone. Most stems reach about 0.9–2 feet [0.28–0.61 metres]. Some reach about 3.25 feet [0.99 metres]. The stiff, green stems bear sticky hairs. Their bases are a little woody. Narrow, green leaves form a rosette at ground level. These lower leaves have fine teeth on their edges. Smaller leaves grow in turn along the stems. These leaves have smooth edges. Resin coats the hairs and gives off a strong camphor scent.

Small flower heads open from late summer into early winter. They grow at branch tips and in upper leaf forks. Each head has yellow rays around its disk florets. These small disk flowers range from yellow to reddish. Two rows of narrow, green bracts grow around each head. Sticky hairs coat these bracts too. The fruit is an achene, pale brown, oval, and hairy. A tuft of fine bristles tops each fruit. The plant makes seeds from September through December. Wind and water move the seeds to new sites. Animals, clothes, and tools or gear can carry them too.

Stinkwort grows in full sun or part shade. It suits sandy soil or shallow, rocky ground that drains well. NC State says growth is slow, but care needs are high. Seeds sprout in winter and spring. Plants appear in May and grow leaves and branches through summer. It grows beside roads, in pasture, and on waste ground. It also grows on sites where people disturb the ground. Its spread threatens farmland. Control relies on care timed to the right stage. These weed traits limit its worth in a garden.

Leaf and stem oils can cause contact dermatitis in people. This is a skin rash caused by touch. Wear gloves and clothes that shield skin when handling it. Livestock and horses can fall ill or die after eating it. Barbed fruit bristles can pierce parts of the gut. The oils can also spoil the taste of meat and milk. Reports note the use of leaves and stems against chicken lice. The plant also yields essential oils. These uses do not show that it is safe to eat.