Annual seed-propagated weed usually germinating in spring, forms many shoots when the soil is supplied with abundant nitrogen. Usually found on humus-rich, nutrient-rich, moist loam soils. Nitrogen remover. Native to the Near East, spread from botanical gardens in the 19th century.
Cotyledons are spatulate to triangular, rounded at top, short-stemmed (Picture 1). True leaves are rounded to broadly ovate, almost cordate (heart shaped) at the base, leaf margin is coarsely crenate (notched), with rounded lobules and scattered erect hairs (Picture 2). Inflorescences are borne individually on long pedicels with curly hairs arising from the leaf axils, sky blue with a lower white tip (Picture 3). Seeds are approx. 2 mm long, peltate and strongly transversely rugose on the back (Picture 4). Approx. 50 to 100 seeds are formed per plant. Viable in the soil for 50 years. Germination occurs at 2-5 °C; the optimum temperature is between 15-25 °C.