Summer Grass Weed (Digitaria sanguinalis)
Common Names
Also known as: summer grass, crab grass
Description
Summer grass is a fast-growing annual weed with sprawling stems that can reach up to 1 metre in length. It has fibrous roots, and its stems spread along the ground, often rooting at the nodes. The stems vary in colour from green to purple.
Leaves are soft, smooth, and usually hairy near the base, measuring 4-8 mm wide. The ligule—a small appendage at the base of the leaf—is a thin membrane, 1-2 mm long.
The seed head consists of 3-13 slender spikes, with flat spikelets arranged in pairs. The fertile florets are pale grey or slightly purple, with mauve filaments and anthers.
This weed is common in lawns, gardens, and disturbed areas. It can be removed by loosening the roots with a knife or trowel, but care is needed to remove all rooted stems, as they break easily.
Similar Species
- Digitaria ciliaris – Nearly identical to D. sanguinalis; microscopic examination is needed for accurate identification.
- Crowsfoot grass (Eleusine indica) – Does not root at the nodes, has fewer leaf hairs, fewer spikes, and a different seed head structure.
- Smallflower finger grass (Digitaria parviflora) – A native species that is mostly hairless, unlike the other Digitaria species.
All of these grasses flower in summer and sometimes into autumn.