Introduced, cool-season, annual  or short-lived perennial herb 50-150 cm tall. Lower leaves are 5-7 cm long, broadly ovate to triangular and lobed to deeply divided. Upper leaves are usually linear and shorter. Flowers are pink, mauve or white and to 10-15 mm long; occurring in dense un-stalked whorls at the upper nodes. Flowering is from winter to summer. A native of Asia and the Pacific, it is a weed of river flats, roadsides and other disturbed places; mostly south of the Bellinger Valley. An occasional minor weed of disturbed areas, which declines when ground cover increases. Control is usually not required.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/73840284@N04">Harry Rose</a> from South West Rocks, Australia
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/macleaygrassman/14446466137/">Leonurus japonicus flowerhead1</a>