Goosegrass

Goosegrass (Eleusine indica) is an annual herb that usually forms a flattened tuft; its upright stems reach 15–60 cm, sometimes sprawling to 1.2 m before turning up. The narrow leaves are 5–35 cm long and soft. The inflorescence consists of 2–6 finger-like spikes (the 'goosefoot') radiating from one point at the tip, each 3–15 cm long — an unmistakable feature. The deep, dense fibrous roots and tough stems make hand-pulling very difficult. The fruit is a small grain with oval, dark-brown seeds.

According to Kew POWO, goosegrass is native to the tropical Old World (Africa to tropical Asia) and has now spread through warm regions worldwide (to about latitude 50°). In Vietnam it grows wild everywhere from the lowlands to the hills — on pavements, verges, paths, dry fields, ditch banks and waste ground. It is a sun-loving, trampling- and drought-tolerant pioneer of compacted, poor soils; listed as an invasive weed in many places, it has evolved resistance to glyphosate, paraquat and glufosinate.

Goosegrass is rich in C-glycosyl flavones — a hallmark of the grasses. The two main flavones isolated from the aerial parts are schaftoside (6-C-glucosyl-8-C-arabinosyl apigenin) and vitexin (apigenin-8-C-glucoside); isovitexin, orientin, isoorientin, saponarin and tricin also occur (Hilu et al., 1978). Modern methanolic LC-MS/MS profiling annotated 65 compounds, including isoschaftoside, vicenin 2, vicenin X, loliolide and adenosine. Roots and stems also contain sterols (β-sitosterol, stigmasterol, 3-O-β-D-glucosyl-β-sitosterol), phenolic acids (p-coumaric, ferulic, gallic), plus terpenes, tannins, saponins, alkaloids and coumarins.

In the folk medicine of many countries goosegrass is used for fever, urinary infection, rheumatism, muscle pain and digestive complaints; in Malaysia the pounded leaves are used to hasten placental delivery and relieve pain, a root decoction for asthma, and in India the seeds and young roots are eaten as food. Modern studies report anti-inflammatory activity (vitexin and schaftoside inhibit 80% and 62% of neutrophil recruitment in LPS-induced mouse lung inflammation at 400 µg/kg), plus antioxidant, antimicrobial, antidiabetic, hepatoprotective, diuretic and anti-urolithiatic effects. The plant is also fodder and a ground cover against erosion.

Goosegrass is considered relatively safe for external use and at folk doses (the root is sometimes treated with caution); prolonged unsupervised use should be avoided while human clinical data are lacking, and plants growing on sprayed or polluted ground may accumulate herbicides or heavy metals (the species has been used in phytoremediation). It is Not Evaluated by the IUCN and not listed by CITES; as a globally common weed it raises no conservation concern — the challenge is instead managing its herbicide-resistant populations in agriculture.