Scientific Names: Persicaria maculosa syn. Polygonum persicaria
Other names: Heartweed, Lady's thumb, Ladysthumb, Ladysthumb Smartweed, Smartweed, Spotted Knotweed, Spotted Ladysthumb, Spotted Smartweed, Persicaria, Redleg, Willow weed
An annual, spreading by seed. Common in arable land. Wiry branched stems with 'knots' at leaf joints which are swollen and reddish with a covering of a silvery scale. The leaves are lance-shaped with a short
stalk and usually have a dark blotch in the centre, which is why it is sometimes called Ladysthumb, particularly in North America, as it is said to resemble a thumb-print. The stems develop a reddish hue as the plant matures, this gives rise to the common name, Redshank.
The seeds can remain dormant for over forty years and often Redshank is one of the first weeds to germinate from imported topsoil or when cultivating a new garden - the seedling has a characteristically long upright first true leaf.
At the tips of stems, a dense spike of small, usually pink flowers appears from May to September - there can be variants with colours from red to white.
Height - up to 60 cm.
Hoe or hand pull, tough branching tap-root. Apply mulch to newly cultivated beds to prevent germination.
Weedkillers to use:-
Dichlobenil prevents emergence of seedlings among established
woody plants, for up to one year.
Glyphosate is a systemic which kills the root
See also Common Knotgrass, Cornfield Knotgrass and Northern Knotgrass which are related and have similar growth habits.
Follow these links for further details on Weeds, Weed Removal and Weed