Digitaria ciliaris, commonly known as Southern Crabgrass, Tropical Finger-grass, or Summer Grass, is an annual grass that is native to tropical and subtropical Old World. It typically grows up to 3 feet tall and forms clumps or patches about 3 feet wide. This species thrives in disturbed areas such as roadsides, cultivated fields, and overgrazed pastures, where it can quickly become dominant. It is characterized by its sprawling habit, flat leaf blades, and finger-like seed heads that appear in summer.

Southern Crabgrass is valued for its rapid growth and ability to cover bare ground quickly, making it useful for erosion control in some situations. However, it is often considered a nuisance in lawns and gardens due to its invasive nature and competitiveness with other plants. It prefers full sun but can tolerate a wide range of soil types, from sandy to clay, provided they are well-drained. This grass requires minimal water once established and can survive in relatively poor soils. In cultivation, it is generally unwanted and efforts are typically focused on its removal or control.CC BY-SA 4.0