Heracleum mantegazzianum – that’s a great Latin name! It’s more commonly known as giant hogweed and the tall dead umbrelliferous spikes left from this summer’s flowerings can be seen on the east side of the River Avon, near the fisherman’s car park just north of Stratford. Everyone knows it can be tall (and can caused nasty blisters…) but it’s worth having a look just to see how high it can grow – easily ten feet tall, rising regally from the willow herb and damp grassland surrounding its huge clumps.
Giant hogweed is usually biennial, forming a rosette of jagged, lobed leaves in the first year before sending up a whitish flower spike in the second and then setting seed. True biennials only live for two years, dying after flowering, but the hogweed does not always obey the rule books and may flower in subsequent summers.
“Turn and run! Nothing can stop them, around every river and canal their power is growing” – that’s from an early Genesis song recorded way back in 1971! A Victorian introduction – and it continues to spread.