Giant Hogweed
NOMENCLATURE
Heracleum: from Greek, ________ the all heal of Hercules, Greek)
warrior ‘hero, whose healing powers were attributed to the herb
OTHER NAMES: cartwheel flower. Tromso palm, (Norw).
BSBI Picture Link to Heracleum mantegazzianum
BOTANICAL DESCRIPTION
TYPE : biennal/monocarpic perennial, perrinates by buds in the axils of basal leaves. 5.5m.
AROMA : strong resinous smell. STEMS : hollow ridged, purple spotted >or< hairy.
UMBELS : compound hairy rays 15-30cm:: Peduncle =or > than rays,
hairy. Terminal hermaphrodite. Lateral male.
LEAVES : lower 250cm, ternately or pinnately divided, coarsley & irregularly serrate, lobes
& > teeth long-acuminate, puberulent beneath, >or< glabrous above. Petiole stout, shortly
sheathing at base. Upper leaves small with a greatly inflated: sheathing petiole.
Cotyledons contracted into a petiole.
BRACTS : several, linear or ovate and long acuminate. Bracteoles linear.
FLOWERS : white, pink, 12mm petals. Sepals triangular, prominent, acute. Outer petals
radiating. Styles form a stylopodium. Fl. 6-7.
FRUIT : 9-11 mm. Elliptical, glabrous, to villous dorsally compressed. Commisure broad.
Mericarps with slender, low dorsal ridges, broadly winged lateral ridges, wings flat and closely
appressed Carpophore present. Vittae solitary, 2/3 > as fruit, 1mm wide at the lower end. Pedicels
10-20mm, hairy. Styles 3 x as > as stylopodium, divergent to recurved. Stigma capitate. 2n=22.
HABITAT : waste ground, near rivers.
DISTRIBUTION : intro. Naturalised in Britain, W. Europe, scattered locations. Native of
SW. Asia. Established colony at 100 year old garden, Hampton-In-Arden. W.Scotland, along
River Ayr, from river side gardens built 1939-45. Large concentration spread
from Edwardian housing estate, Colinsburgh, Fife. In coastal fen Aldeburgh, Suffolk.
Side of Art Deco Hoover factory, W.London. Marina Of Ilfracombe, Devon. Launceston
recycling centre Sides of Toll bridge, Nottingham outskirts. Large
riverside sweep along River Usk, Abergavenny.
BSBI Distribution Map for Heracleum mantegazzianum (UK)
POISONING PRINCIPLES
Causes phytophytic sun. In 1970 large hospitals with blisters, on their lips from using
stems as peashooters. An eradication programme was implemented with little effect.
GARDEN USES
Grown for 150 years in curious Victorian shrubberies. Seeds offered in 1849 by Hardy & sons
of Maldon, Essex. 1870, William Robinson recommends it as suitable for rough places on river bank
gardens. There is a long established colony in a 100 yr old garden in Hampton in Arden. In Norway it is regarded with affection and is featured on postcards.
EXTERNAL LINKS FOR Heracleum mantegazzianum
These links to trusted websites and institutions may provide in depth or additional information regards cultivation, chemistry, edibility, images etc. for the species. Links last updated Aug 2012.
Wikipedia (EU) NatureGate (FIN)
Bio Info (UK) APHOTOFLORA (UK)
Bio Images (UK) Forestry Service (USA)
Non Native Species Secretariat (UK) Q Bank (NETH)
'Online Guide To Umbelliferae Of The British Isles' Compiled By J.M.Burton 2002