An annual weed with round or oval leaves on stems, 4" — 16" long. Upper leaves are arranged alternately along the stem; lower leaves are arranged in pairs. Small, deep blue flowers with white centers are borne on stalks, 3/8" — 1" long. The entire plant is covered with hairs. Mature plants are compressed (low growing) when mowed frequently.
It flowers throughout the year and is self fertile. It can be found in fruit throughout the year. The average number of seeds per plant is 2000 but a large plant may produce up to 7000 seeds. There may be two generations in a year. The seed rain from plants that emerged after cultivation in April extended through to July, and increased the seed numbers in soil from 1,720 to 37,580 per 1000 sq. ft.
Seedlings emerge from February to November with peaks of emergence between May and September.
In the field, 85% — 100% of seedlings emerge from about 1" from the surface of sandy and clay soils with the odd seedling emerging from down to 2". Seedlings from deeper in the soil take longer to emerge and thus prolong the flush of emergence.