Gen info
- Paspalum is a genus of plants in the grass family Poaceae, widespread across much of Asia, Australia, and the Americas. Commonly known as paspalum, bahiagrasses, crown grasses or dallis grasses—warm-season C4 grasses, most diverse in subtropical and tropical regions.
- The genus Paspalum has about 200 species widely distributed in the tropics and subtropics of both hemispheres. Many provide forage or pasture grass for cattle and horses.
- Paspalum conjugatum, commonly known as carabao grass or hilo grass, is a tropical to subtropical perennial grass, originally from the American tropics, now widely naturalized in tropical Southeast Asia and Pacific Islands. It was first described in 1772 by the Swedish botanist Peter Jonas Bergius. (7)
- It is particularly abundant in the Philippines, where the English name "carabao grass" originated, named after the carabao, the local water buffalo breed, for which it is suitable forage, and, hence, the local common name, carabao grass or buffalo grass. (7)

Botany
• Laua-laua is a gregarious stoloniferous grass. Stems are spreading and branching below withe the flowering branches 20 to 70 centimeters high. Leaves are narrow lanceolate, flat and thin, glabrous, 8 to 20 centimeters long, 5 to 15 millimeters wide. Spikes are two, terminal, slender and 6 to 12 centimeters long. The spikelets are imbricate, 1.2 to 1.4 millimeters long, pale-green, plano-convex, the empty glumes with long, soft, white marginal hairs.

• Paspalum conjugatum has a creeping stoloniferous habit. Culms are branching and slightly compressed dorsoventrally, they are usually reddish to purplish in color. Leaf sheaths are strongly flattened, usually 30 to 50 mm (1.2 to 2.0 in) long and hairy around the nodes. Leaves are smooth, around 8 to 20 cm (3.1 to 7.9 in) in length, and 5 to 12 mm (0.20 to 0.47 in) in width, linear to lance-like in shape, tapering to a point. Inflorescence are characteristically T-shaped, with two (rarely three) racemes. (7)

Distribution
- Introduced.
- Grass is found in abundance in open waste places and settled areas, about towns, along trails, streams throughout the Philippines.
- Considered a weed but sometimes planted as a coarse ground cover grass.
- Native of tropical America.
- Now pantropic.
- A serious weed among agricultural crops.

Constituents
- Phytochemical study yielded glycosides, saponins and steroids.
- Phytochemical screening of crude extract of P. conjugatum yielded sterols +++, triterpenes ++, flavonoids +++, alkaloids +, saponins ++, glycosides ++, tannins +++. (see study below)   (15)
- Phytochemical analysis yielded four phytochemicals: alkaloid, tannin, flavonoid, and glycosides, significantly present in n-hexane and ethanol extracts. Proximate analysis of the leaves powder showed 3.56, 9.76, 3.22, and 27.08% for moisture content, total ash, acid-insoluble ash, respectively. (see study below) (16)
- Study of three different samples of carabao grass for secondary metabolites yielded cyanogenic glycosides. (see study below) (17)

Properties
- Studies have suggested antifungal, fatty acid synthase inhibitory, antibacterial, hypoglycemic, antioxidant, phytoremediative properties.

Parts utilized
Roots, leaves, whole plant.

Uses
Folkloric
- Decoction of fresh roots are taken internally for diarrhea.
- Manobo tribes of Agusan del Sur drink decoction of leaves three times daily for fever and urinary tract infections. (22)
- In Africa, leaves used for fever, debility, stomach troubles and pulmonary afflictions; roots used for diarrhea and dysentery
- In Gabon, pounded with the leaf of Desmodium salicifolium and applied as compress for contusions, sprains and dislocations.
- In Congo, the leaves used with Macaranga sp and Renealmia sp. in a vapor bath for fever.
- In Cameroon, decoction of leaves, softened in hot ashes and ground in water, used for dysentery. (6)
- In Trinidad, leaf infusions used for fever.
- In Malaysia, young leaves are pounded and applied as paste onto wounds and cuts.
- In West Papua, leaves used for wound healing. (13)
- In Ecuadorian Amazon, infusion of the plant used for headaches. (The ethnobotanical efficacy may be due to an ergot-like fungus infestation.) (5)
- In Zaire, as antivenom, decoction of whole plant is rubbed on the bite with the oil of Lebrunia bushaie. (2)
- Leaves or crushed spikelets applied to wounds and sores. (A hemostatic glucoside content is believed to promote faster blood clotting). (18)
Others
- Forage: Usually not palatable to cattle, especially in the flowering stage. When grown for forage, they are usually cropped continually, to maintain palatability. (7) In Africa, grass provides good grazing for cattle and horses, taken before seed-set.
- Veterinary: Cats and dogs said to eat the leaf as purgative.
- Landscaping: Used as landscaping cover-grass.

Studies
• Fatty Acid Synthetase Inhibitor / Antifungal: FAS has been identified as a potential antifungal target. In a study that included Paspalum conjugatum, FAS was prepared from thirteen compounds including three new natural products, representing five chemotypes: isoflavones,, flavones, biflavonoids, hydrolyzable tannin-related derivatives and triterpenoids. Although there were several antifungal components in the set, FAS inhibitory activity could not be correlated with antifungal activity. (3)
• Phytoremediation / Lead: Study showed carabao grass as a potential phytoremediator, absorbing small amounts of Pb in soils. (In a comparative study, vetivergrass showed the most beneficial characteristics. Cogon grass showed to be more tolerant to Pb-contaminated soil compared to carabao grass. (10)
• Phytoremediation / Mercury / Effect on Maize Growth: Study showed P. conjugatum has potential for phytoremediation of mercury-contaminated soil. Growth and biomass production in maize grown on remediated soil increased after phytoremediation with P. conjugatum. (12)
• Antimicrobial: Study evaluated the P. conjugatum for phytochemical content and antimicrobial efficacy against Staphylococcus aureus.  Antimicrobial testing showed zone of inhibition of 10 mm. (see constituents above) (15)
• Antioxdant / Leaves: Study evaluated various extracts (n-hexane, chloroform, ethanol, water) of powdered leaves of P. conjugatum for proximate analysis and antioxidant activities.  Antioxidant testing included reducing power assay, total antioxidant activity, total phenolic content, total flavonoids, and ferric ion reducing power. All extracts showed significant presence of antioxidants. The ethanol extract showed good antioxidant activity with good phenolic and flavonoid content compared to other solvents. (see constituents above) (16)
• Cyanogenic Glycosides: Study of three different samples of carabao grass for secondary metabolites yielded cyanogenic glycosides, which can be harmful to humans in large doses. Study recommends that it should be properly hydrolyzed prior to consumption to avoid cyanogenic poisoning. It is advised use for animal grazing or for aesthetic purposes only. Further studies are recommended on the cyanogenic glycoside content for specific type and concentration. (17)
• Antibacterial: Study evaluated the antibacterial activity of P. conjugatum extracts against Staphylococcus epidermis and Escherichia coli. Results showed carabao grass extracts concentration of 50, 75, and 100% showed antibacterial activity against S. epidermis, but showed no activity against E. coli. (19)
• Hypoglycemic: Study evaluated the hypoglycemic effect of P. conjugatum on blood glucose levels of Dexamethasone-induced Mus musculus (male albino mice). Glibenclamide was used as positive control, distilled water as negative control. Mice treated with methanolic grass extract showed mean blood glucose of 91.88, compared to Glibenclamide at 63.123 and distilled water at 127.19. Results suggest the methanolic extract possess hypoglycemic properties. Clinical trials were suggested to evaluated potential for use of plants as alternative treatment. (20)
• Phytoremediation of Contaminated Rare-Earth Mining Sites: Over-exploitation of rare-earth elements cause cadmium (Cd)- and lead (Pb)-contamination of rare-earth mine tailings. Study evaluated the hyperaccumulating perennial herb P. conjugatum for its phytoextraction potential for removing metals in a hydroponic experiment. P. conjugatum showed effective extraction of Pb and Cd with transfer coefficients of 0.89 and 0.85. Bacterial genera Chloroflexi, Acidobacteria, and Actinobacteria were predominant in the restored soils. The grass was drought-tolerant and exhibited enhanced enzymatic activity. Results suggest P. conjugatum can be used for effective phytoremediation of Pb- and Cd-contaminated soils. The restored soil was deemed safe for agricultural production. (21)
• Phytoremediation Potential for Reduction of Copper, Manganese, and Iron in Copper Tailings: Study evaluated the phytoremediation potential of Carabao grass and measured the copper, manganese, and iron concentration in tailings. The most effective setup ration is 0%Compost-100% Tailings, which showed greatest copper reduction and least increase in iron and manganese. The survivability of carabao grass and ability to accumulate copper suggests it to be an accumulator of copper and excluder of iron and manganese. (23)

Availability
- Wild-crafted.