Meadow hogweed and giant hogweed are widespread in Germany. While the former is classified as slightly toxic to toxic, the latter was named poisonous plant of the year in 2008.
In a nutshell
- Meadow Bear Claw is the little brother of the Giant Bear Claw
- Giant Bear Claw is very poisonous
- There is a risk of confusion because there are only a few unique features
Bear Claw (Heracleum)
Bear's Claw is a genus of plants that includes about 70 species. Only the meadow hogweed and the Austrian hogweed (Heracleum austriacum), which only occurs in the eastern Alps, are considered native. The type species of the plant genus is the meadow hogweed, i.e. the other species look similar to it, but have more or less big differences. There is a risk of confusion in this country, especially with the giant hogweed (Heracleum mantegazzianum). Because this neophyte, which originally comes from the Caucasus, has run wild from gardens and parks and is now on the list of invasive plants in the EU.
toxicity
Heracleum is poisonous, regardless of whether it is meadow hogweed or giant hogweed. The contained toxins belong to the substance class of furocoumarins. These can trigger phototoxic reactions (UV-A sensitivity) in sunlight or daylight and when touched. The symptoms of "meadow dermatitis" are striped, leaf-shaped or web-like skin changes that can appear immediately or after a day or two.
Strong sunlight shows:
- redness
- blow
- a severe itching
- a spread down the arms and legs
With weak solar radiation show:
- redness
- swelling
- partly without strong inflammatory reactions
However, depending on the strength of the UV-A radiation, the skin heals after one to four weeks. During the healing process, there is severe skin pigmentation, which can show up for many months.
Notice: Since the concentration of photosensitizing substances in giant hogweed is very high, you should avoid touching this Heracleum species or wear full protective clothing (including face protection) when handling the plant.
Determine giant and meadow hogweed
In the following, we will explain to you which characteristics you can use to distinguish meadow hogweed from giant hogweed.
Meadow Hogweed (Heracleum sphondylium)
Growth:
- perennial herbaceous plant
- Growth height between 50 and 150 centimeters (depending on region and location)
- thick, branched main axis
stem:
- angular furrows
- hollow
- rough haired
- 0.5 to 2 centimeters thick
Source: AnRo0002, 20220522 Heracleum sphondylium4, edited from Plantopedia, CC0 1.0
Leaves:
- simply feathered
- plump
- slightly hairy
- grey-green
- blunt sawn
- incised into unequal lobes
Notice: The leaves of the meadow hogweed are considered large, but are noticeably smaller than those of the giant hogweed.
Blossom:
- double umbel inflorescence with many flowers
- up to 25 centimeters in diameter
- 12 to 40 rays
- Flower color: white and usually slightly greenish or light pink
- Flowering period: June to September / October
Giant Hogweed (Heracleum mantegazzianum)
The differences in size are highlighted as the clear characteristics of the Hercules perennial, as Heracleum mantegazzianum is also called. In other words: In the case of the giant hogweed, in principle everything is much larger than in the case of the meadow hogweed. Nevertheless, you should use the stem of the plant as a guide, as this shows large, dark spots in the giant hogweed.
Growth:
- biennial herbaceous plant
- Growth height of up to 100 centimeters in the first year (beginning of May)
- Growth in the second year up to 300 centimeters (end of June), in rare cases also 500 centimeters
- thick, branched main axis
Notice: The Hercules perennial usually grows biennially. The plant only gets older if it does not flower and fruit ripen in the second year.
stem:
- Difference to Wiesen-Bärnklau: many, large, wine-red or dark spots
- hardly furrowed
- hollow
- moderately hairy you
- 2 to 10 centimeters thick at the base
(lower) leaves:
- up to 100 centimeters long (with handle up to 300 centimeters)
- pointed shape, appear rather elongated
- three to nine-part leaf blade
- sharply sawn
- lateral leaf sections deeply divided, up to 100 centimeters long and more than 20 centimeters wide
- hairy underside
Blossom:
- giant bud (surrounded by a wide leaf sheath)
- double umbel inflorescence with many flowers
- 30 to 50 centimeters in diameter
- 30 to 150 rays
- up to 80,000 individual flowers
- Flower color: white
- Flowering period: June to July
frequently asked Questions
Do I have to report specimens of giant hogweed?There is no obligation to register in Germany. However, since it is an invasive plant that crowds out native vegetation, it is recommended that localities report it. Ideally, you should send the Bärenklau expert a photo of the relevant area.
What about the risk of confusion with young plants?Since the Hercules perennial can already sprout in February, it has a growth advantage over native plants. The leaves are a good indication, because they have reached a stately size when the native vegetation only begins to sprout.
Where does the giant hogweed grow?The plant makes no special demands on the soil. It grows on banks, at the edge of the forest, meadows, fallow land or pastures. At high altitudes, it can be confused with the Austrian hogweed. As this one causes similarly severe burns, you should also stay away from this species.