Water Parsnip, Wideleaf waterparsnip
Sium latifolium
Family: Apiaceae or Umbelliferae
What it is like
Sium latifolium is a PERENNIAL growing to 2 m (6ft 7in). See above for USDA hardiness. It is hardy to UK zone 6 and is not frost tender. It is in flower from July to August. The species is hermaphrodite (has both male and female organs) and is pollinated by Beetles, flies, bees. The plant is self-fertile. Suitable for: light (sandy) and medium (loamy) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers wet soil and can grow in water.
Height (m): 2
Where it is found
Fens and other wet places, often in water, avoiding acid conditions.
Most of Europe, including Britain, excluding the northwest, Portugal, Greece and Turkey.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
Leaves - cooked. Some caution is advised, see the notes above on toxicity.
Medicine
Rating: 0
Other
Rating: 2
An essential oil is obtained from the seed.
Essential: Essential oils that are used in perfumery, medicines, paint solvents, insect repellents etc.
Scented Plants: Plants noted for their scent
How it is grown
Prefers a light, rich, moisture retentive soil in full sun. A plant of wet ground and shallow water, it grows best in about 20cm of water.
Propagating it: Seed - sow late winter to early spring in a cold frame. The seed can be slow to germinate. Prick out the seedlings into individual pots when they are large enough to handle and plant them out in the summer if they are large enough. Otherwise, grow them on in a cold frame for their first winter and plant them out in the following spring. Division in early spring just before new growth begins. Use the side roots. Larger divisions can be planted out direct into their permanent positions. We have found it best to pot up the smaller divisions and grow them on in a lightly shaded position in a cold frame, planting them out once they are well established in the summer.
Best place to grow: Pond; Bog Garden;
Habit: Perennial
Hardiness: 5-9
Growth:
Soil: Light (sandy), medium
Shade: No shade
Moisture: Wet, water
Things to keep in mind
The entire plant, and especially the root, is poisonous. There is no firm proof of this.