Distribution of Giant Hogweed in Yorkshire and its effects on ecosystems

摘要

Giant Hogweed (or Cartwheel Flower) Heracleum mantegazzianum, of the family Apiaceae, was introduced to the United Kingdom in 1893 as a garden novelty from the Caucasus Mountains by Victorian plant collectors (Pysek et al., 2007). It is the biggest herbaceous plant in Britain, a poisonous invasive weed which can cause third-degree burns if touched. It is spread by wind and successfully establishes when seeds (1500 seeds per flower head) fall into rivers and are carried downstream before settling in muddy banks. It can grow up to 5m tall with a herbaceous stem 5-10cm in diameter (Fig.2 pl89). It is a self-fertilising biennial plant with white flowers, reproducing only once in its lifetime. Booy & Wade (2007) report that this plant does not reproducevegetatively but relies exclusively on reproduction by seed. It grows in gardens, woodlands, along riversides and on heathlands.