Giant hogweed

Heracleum mantegazzianum

''Heracleum mantegazzianum'', commonly known as giant hogweed, cartwheel-flower, giant cow parsnip, hogsbane or giant cow parsley, is a plant in the family Apiaceae. In New Zealand, it is also sometimes called wild parsnip, or wild rhubarb. It typically grows to heights of 2 to 5.5 m . Superficially, it resembles common hogweed , ''Heracleum sosnowskyi'', or garden angelica . It is phototoxic and considered to be a noxious weed in many jurisdictions. Giant hogweed is native to the Caucasus region and Central Asia. It was introduced to Britain as an ornamental plant in the 19th century, and it has also spread to many other parts of Europe, the United States, and Canada.

The sap of giant hogweed causes phytophotodermatitis in humans, resulting in blisters and long-lasting scars. These serious reactions are due to the furocoumarin derivatives in the leaves, roots, stems, flowers, and seeds of the plant.
Heracleum mantegazzianum Flora,Forest,Heracleum mantegazzianum,Macro,Plants,poisonous,toxic

Appearance

Giant hogweed has a stout, bright green stem that is frequently spotted with dark red and hollow red-spotted leaf stalks that produce sturdy bristles. The stems grow to more than 2 m high. The hollow stems vary from 3–8 cm in diameter, occasionally up to 10 cm . Each dark red spot on the stem surrounds a hair, and large, coarse white hairs occur at the base of the leaf stalk. The plant has deeply incised compound leaves which grow up to 1–1.7 m in width.

Giant hogweed is a biennial or monocarpic perennial,:827 the plants usually begin dying after they have set seed. It usually flowers in its second year from late spring to midsummer, with numerous white flowers clustered in an umbrella-shaped head that is up to 80 cm in diameter across its flat top. The plant produces 1,500 to 100,000 flattened, 1-centimetre -long, oval, dry seeds that have a broadly rounded base and broad marginal ridges. Tall dead stems may mark its locations during winter.

Defense

The sap of the giant hogweed plant is phototoxic; when the contacted skin is exposed to sunlight or to ultraviolet rays, it can cause phytophotodermatitis . Initially, the skin colours red and starts itching. Blisters form as it burns within 48 hours. They form black or purplish scars that can last several years. Hospitalisation may be necessary. Although many media reports on giant hogweed suggest the plant can lead to temporary or permanent blindness, existing research on the plant does not back up this claim.

These reactions are caused by the presence of linear derivatives of furanocoumarin in its leaves, roots, stems, flowers, and seeds. These chemicals can get into the nucleus of the epithelial cells, forming a bond with the DNA, causing the cells to die. The brown colour is caused by the production of melanin triggered by furocoumarins.

Authorities advise that children should be kept away from giant hogweed, that protective clothing, including eye protection, should be worn when handling or digging it, and that if skin is exposed, the affected area should be washed thoroughly with soap and water and the exposed skin protected from the sun for several days.

Cultural

The 1971 album ''Nursery Cryme'' by the progressive rock group Genesis contains a song called "The Return of the Giant Hogweed". The lyrics describe a murderous attack on the human race by ''Heracleum mantegazzianum'', long after the plant was first "captured" and brought to England by a Victorian explorer.

References:

Some text fragments are auto parsed from Wikipedia.

Taxonomy
KingdomPlantae
DivisionAngiosperms
ClassEudicots
OrderApiales
FamilyApiaceae
GenusHeracleum
SpeciesH. mantegazzianum
Photographed in
Germany