Commelina benghalensis, or tropical spiderwort, is an annual or perennial, creeping herb that is on the Federal Noxious Weed List.
Foliage
Leaves are alternate, lily-like, 1.2-2.8 in. (3-7 cm) long and often have reddish hairs towards the tip.
Flowers
Aboveground flowers are very small with relatively large lilac to blue petals and are present from the spring into the fall. Underground flowers, which grow on burrowing rhizomes, are white and very small.
Fruit
Fruits are ovoid capsules.
Ecological Threat
Commelina benghalensis invades areas with moist soil including roadsides, grasslands and other disturbed areas. It is especially problematic in pastures and crop fields where it forms dense, pure stands that can smother other plants such as low-growing crops. Commelina benghalensis is native to Asia and Africa and was first found in the United States in 1963.