Galeopsis tetrahit, the common hemp-nettle or brittlestem hempnettle, is a flowering plant in the family Lamiaceae, native to Europe and northwestern Asia.
It is a herbaceous annual plant growing to 1 m tall; it is a pioneer species and thrives on disturbed sites or roadsides. The plant looks like mint but is taller. The stems have reflexed hairs and swollen nodes. In cross section, the stem is square. The leaves are rhombic to elliptic, with coarsely to bluntly serrate edges. The flowers are multicoloured, with purple, pink, or white areas. diminutive, bilateral and snapdragon-like, and are mostly visited by bumblebees.
Common hemp-nettle is an erect annual plant and grows to a height of about 20 to 70 cm (8 to 28 in). The stem branches occasionally and is squarish and hairy, with glandular hairs on the upper part of the plant. The nodes are swollen and widely spaced and the pale green, stalked leaves are in opposite pairs. The leaf blades are hairy and are ovate with a long tapered tip and with regular large teeth on the margin. The inflorescence forms a terminal spike and is composed of whorls of pinkish flowers with dark markings on the lower lip.
This plant might be poisonous
How to get rid of:
Hand pulling needs to be done carefully to ensure there is a
minimum of soil disturbance. Many weeds flourish when soil is
disturbed.
Removal of small weeds can be achieved by placing one hand flat
on the ground with the weed between two fingers. As the hand is
pressed toward the ground the second hand can carefully remove
the weed.