Scientific name: Sium latifolium L.
Common name: Greater Water-parsnip
Description
Habit: A hairless perennial, to 2 m high.
Stems: Erect, hollow.
Leaves: Submerged leaves 2-3 pinnate in Spring; lower aerial leaves pinnate, leaflets large up to 15 cm, 4-5 pairs; leaflets oval and toothed.
Flowers: White in terminal umbels, with about 25 rays; bracts and bracteoles several, conspicuous and often leafy; petals 5, free; stamens 5; ovary inferior and 2-celled.
Fruits: A schizocarp, 2.5-4 mm, longer than wide, with thick ridges.
Habitat: Rivers and ditches.
Distribution: Very local.
Native status: Native
Of conservation interest: Yes