hogweed

Heracleum sphondylium is a herbaceous, flowering plant. It is a tall, roughly hairy plant reaching up to 2 metres (6 ft 7 in) in height. The hollow, ridged stem with bristly hairs arises from a large tap root. The leaves can reach 50 centimetres (20 in) in length. They are once or twice pinnate, hairy and serrated, divided into 3–5 lobed segments. Heracleum sphondylium is most commonly a polycarpic perennial plant, not a biennial as sometimes claimed. The flowers are arranged in umbels, either flat or slightly convex, 4–25 cm (1.6–9.8 in) in diameter, usually with 10–25 hairy, somewhat unequal rays, each 2–12 cm (0.8–4.7 in) long. Each flower has five white or rarely pinkish-white to purplish petals. The central flowers of the umbel have radial symmetry (actinomorphic), while the flowers around the perimeter of the umbel have bilateral symmetry (zygomorphic) since the outermost petals are enlarged. The winged fruits are flattened schizocarps, elliptical to rounded and glabrous, about 7–12 mm long. The characteristic 'farm yardy' smell or the observation that pigs would eat the foliage and roots of hogweed is perhaps the origin of its common name. Heracleum sphondylium is smaller than Heracleum mantegazzianum (giant hogweed) and Heracleum sosnowskyi (Sosnowsky's hogweed). …

Heracleum sphondylium is native to most of Europe, western Asia and northern Africa. For example, it occurs in southern and southwestern Poland but much less so in other parts of the country. The species has been introduced into North America. In particular, it has been introduced to eastern Canada, but reports of H. sphondylium in Canada are rare. Some authorities claim that Heracleum sphondylium subsp. sibiricum (a synonym of Heracleum sibiricum) has been introduced in the United States, but in New England, botanists have been unable to identify the taxon to subspecies rank. The plant is common in grassland, herb-rich meadows, in hedges, meadows and woods, road verges and railway embankments, waste and cultivated ground. It grows especially well on moist, improved nitrogen-rich soils. It can occur in mountain areas up to 2,500 m (8,200 ft) of altitude.

In Europe, the primary flowering season of Heracleum sphondylium subsp. sphondylium extends from June to September, with peak flowering and seed ripening occurring in July and August, respectively. In Great Britain, seed dispersal occurs during late September and early October, which usually coincides with the winds of the September equinox. The flowers are pollinated by insects such as beetles, wasps and especially flies. As its name suggests, the small picture-winged fly Euleia heraclei is found on hogweed. The leaves are commonly mined by the larvae of the leaf miner Phytomyza spondylii. Heracleum sphondylium was rated in the top 10 for most nectar production (nectar per unit cover per year) in a UK plants survey conducted by AgriLand, a project supported by the UK Insect Pollinators Initiative.

Borscht derives from an ancient soup originally cooked from pickled stems, leaves and umbels of common hogweed. The young shoots are considered excellent eating by many foragers. In eastern European countries and especially Romania, H. sphondylium is used as an aphrodisiac and to treat gynecological and fertility problems and impotence. It is also sometimes recommended for epilepsy. However, there are no clinical studies to prove its efficacy at treating any of these problems. The seeds can be dried and used as a spice, with a flavour similar to that of cardamom.

The species name sphondylium, meaning "vertebrate" (from Greek σπόνδυλος, spondylos 'vertebra') refers to the shape of the segmented stem.