Torilis arvensis aka Spreading Hedge Parsley

Torilis arvensis is an annual in the carrot family, Apiaceae. Common names include field hedge parsley and spreading hedge parsley. Its native range spans Europe to Central Asia and Pakistan. It also includes Macaronesia, North Africa, and the Arabian Peninsula. It has become naturalized in North America. There, it grows beside roads, in thickets, and on disturbed ground. It also occurs in woods after logging. Kew places it in the temperate climate zone.

This upright plant grows 1–3 feet [0.30–0.91 metres] tall. Its spread is about 0.5–1 foot [0.15–0.30 metres]. It has a taproot and grows at a moderate rate. Fine white hairs cover its slim, round, green stems. The stems have no scent. Green leaves grow alternately on long, thin stalks. Their triangular outline and divided blades give them a fern-like look. Leaves are pinnate or bipinnate, with toothed or lobed edges. Short white hairs cover their upper surfaces. Leaves near the flowers are narrower, with lance-shaped or narrow oval blades.

Flowers open from early to mid-summer in compound umbels. Each cluster spans about 0.17–0.25 feet [0.05–0.08 metres]. An umbel has about eight smaller clusters, each bearing several tiny flowers. Each flower has five unequal petals and five stamens. The petals are white, sometimes flushed pink or red. Oblong, burr-like fruits follow in summer and autumn. They turn from pinkish green to brown as they ripen. Straight or curved bristles cling to fur and clothes. This helps carry the seeds to new sites.

The plant grows in full sun and well-drained soil. NC State lists clay and shallow, rocky soils as suitable. It also lists neutral to alkaline soil and tolerance of occasional dryness. The evidence gives no hardiness zone or frost limit. Its annual life cycle ends with seed production. It seeds itself freely, and NC State rates its maintenance needs as high. Its main listed garden problem is weediness, rather than a named pest or disease.

The flowers draw bees, flies, and wasps that visit for nectar. Black swallowtail caterpillars feed on the leaves. These traits give the plant value for insects. Yet its ready spread can make it troublesome in planted areas. The supplied sources give no supported food use or medicinal use. They also provide no toxicity assessment for people or pets.