Urochloa mutica is a perennial semi-prostrate grass 2-5m tall. The stems are erect or prostrate with densely haired nodes.
It can be easily identified by its stems which have distinct swollen nodes and its flower spikelets which consist of green or purplish glumes.
Urochloa mutica Classification
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Spermatophyta
- Subphylum: Angiospermae
- Class: Monocotyledonae
- Order: Cyperales
- Family: Poaceae
- Genus: Urochloa
- Species: Urochloa mutica
- Common Names: California grass, Bancroft grass, Buffalo grass, Dutch grass, Mauritius signal grass, Signal grass, Tall panicum, Water grass, Giant Couch, and Carib grass.
Nativity and Distribution
Para grass is native to Western and Northern Africa and parts of the Middle East. It is now found in other regions including:
- Australia
- Asia
- Southern United States
- Central and South America
- New Zealand
Physical Characteristics
- Leaves: Leaf sheaths, sparsely or densely haired with leaf blades 7.5-35 cm long
- Fruits: Caryopsis 1-8.2mm long
- Stems: Culms. They can grow up to 2-5m.
- Flowers: 2.5-3.5 mm long flower spikelets
- Roots: Adventitious roots
Urochloa mutica is a perennial stoloniferous grass that can grow up to 2-5m tall. It is easily recognizable by its distinct swollen nodes on the stem and its flower spikelets that consist of green or purplish glumes.
Culms are upright, hairy, and mostly branched, with roots produced at the lower nodes. The leaf sheaths enclose the stem with spreading leaf blades 3-20mm wide and 7.5-30 cm long. The leaf blades are linear, glabrous, or sparsely hairy, with entire margins and an acute apex.
Flowerheads are arranged in a panicle 5-10 cm wide and 10-25 cm long with 3-10 spreading spike-like branches.
The paired spikelets are elliptical and also slightly branched, with the secondary branches consisting of 3-6 flower spikelets. Individual flower spikelets consist of green or purple bracts and two tiny florets.
The lower floret contains the male parts and the upper floret contains the male and female parts and typically produces the seeds. Flowering occurs sporadically throughout the year.
The seeds are light brown, elongated, and narrow in shape, 1-2mm long, and may have short awns.
- Life Cycle: Perennial
- Seeds: Does not produce many viable seeds
- Climate: Tropical and subtropical climates
- Dispersal: Wind, water, and animals
U. mutica behaves as a perennial and reproduces by seed and vegetatively by stolons. The few viable seeds produced can germinate in the right conditions, allowing for rapid establishment of the grass.
However, Pasto pare mainly spreads by creeping stems that grow laterally, extending several meters from the parent plant. New shoots and roots emerge along the stem.
When the root comes into contact with the soil, it roots down to form a new plant, propagating the growth cycle.
The seeds and stem fragments are mainly dispersed by wind, animals, and flood waters. Long-distance dispersal occurs mainly due to its use as a pasture grass.
Similar Plants
- Urocholoa decumbens
- Urochloa brizantha
- Urochloa arrecta
Uses
- It is used as forage and fodder grass for livestock.
- The grass is used to control soil erosion on slopes, riverbanks, and other seasonally waterlogged areas.
- It is used in land reclamation.
- It is used as an ornamental grass for its dense cover and lush appearance.
- The grass is used in cultural activities such as thatching and craft making.
Impact on Farms and Environment
While U. mutica can provide nutritious fodder for livestock and help in soil erosion control, its negative impact far outweighs its benefits.
Para grass is listed as a weed in at least 34 countries across the tropical and subtropical regions worldwide and is a serious weed in countries like Malaysia, Fiji, Peru, Australia, the Pacific Islands, and Mexico.
The weed can block irrigation ditches in sugar cane fields, leading to damage and poor crop yield.
As a semi-aquatic plant, it can choke out riverbank and floodplain vegetation through competition, its fast and dense growth, and allelopathic properties.
In Australia, for instance, it has invaded wetlands in Queensland and New South Wales, destroying breeding habitats for waterbirds like the Magpie goose.
Para Grass is also a weed of streams, swamps, marshes, bottomland forests, and lake shorelines, where dense stands can impede transportation and alter their water-carrying capacity, increasing flood risks in water systems.
Scotch grass is known, for instance, to cause significant damage to hydroelectric dam infrastructure in Brazil.Â
Control
- Mechanical control: Cutting, burning, and roller-chopping
- Chemical control: Herbicides like glyphosate and Imazapyr
Cutting and removing the stolons can provide effective control for small infestations. For large infestations, cutting, burning, or roller-chopping followed by flooding can help eradicate the weed, especially for areas where herbicides are not an option.
Where applicable, glyphosate and imazapyr are the commonly used herbicides for para grass control. Always read the label and follow the manufacturer’s instructions when using herbicides. For detailed information, consult an expert.
Biological control agents against U. mutica are yet to be developed.
Lead Editor for Insight Weeds.