This variegated clone of Yellow Archangel, Lamium galeobdolon ssp. argentatum 'Variegatum' (sometimes 'Florentinum') is very rampant and will quickly cover the ground. It grows in dense shade and in dry conditions with plenty of humus present. For this reason it is sometimes used as ground-cover in difficult areas under trees, but great control is required to keep it in check.
The leaves are in opposing pairs and have long petioles, arising from the nodes where branching can occur and roots can grow if they touch the ground. The distinguishing white markings increase as the leaf matures and during cooler conditions the same purplish colour of the square stems fills the centre portion along the main veins. The surface is rough and hairy with a toothed edge. When crushed they have a mint-like aroma.
Between April and June upright stems grow and these bear lemon-yellow flowers similar to other members of the Mint Family - funnel-shaped, with an upper hood and a lower lip with orange guide to attract pollinators to its sweet nectar. They are borne in clusters of up to 10, attached to the leaf axils.
It is easily pulled up, so small areas can be cleared by hand ensuring that all fragments of the stems are removed. It does not survive continuous close mowing. The fibrous roots do not regrow provided no part of the growth point is still attached. It does not appear to produce seed and reproduces vegetatively. Do not add to the compost heap, unless it has been allowed to dry out completely. Better to put in the recycling bin.
Glyphosate is a suitable weedkiller to use, as it is taken into the perenniating stems, spray or paint on depending on the
situation. Use when the plants are growing well and are moving their sap at a higher rate. The greater the area of leaf that can be treated the better and resist the temptation to remove any topgrowth for at least two weeks after application.
See also Ground Ivy, which has a similar growth habit.
Follow these links for further details on Weeds, Weed Removal and Weed Prevention.