Recognize the problem
Family: Cyperaceae (sedge family)
Common names: Lesser fimbristylis, grass-like fimbristylis, fiveangle fimbry.
Thai: หญ้าหนวดแมว Ya nuad maew; หญ้ารัดเขียด Ya rat khiat (Central, Chai Nat); หญ้าหนวดปลาดุก Ya nuat plaa duk (Surat Thani).
Tufted, leafy annual or short lived perennial erect sedge with fibrous root system, without hairs, strongly tillering, 40-120 cm high.
Leaves: Stiff and thread-like (1.5-2.5 mm wide), up to 40 cm long, without prominent midrib.
Flowers: 6−10 cm long; rather lax and diffuse compound umbel with 6−50 spikelets; spikelets reddish brown, 2−4 mm long and either round or acute at apex.
Fruits/Seeds: Straw-coloured or pale ivory three-angled nut, 0.2−0.3 mm long. Produces 10,000 seeds per plant which can germinate immediately after reaching maturity. Seeds can remain viable for more than one year.
Introduced: As contaminated seed.
Habitat: Occurs in damp, open waste places and along waterways.
Spread: Seeds are dispersed by water, wind and human-related activities or they can be eaten by cattle and germinate near droppings.
Invades: Abundant weed in rice plantations throughout tropical and subtropical regions.
Impacts: Fimbristylis quinquangularis competes with crops for light and nutrients. The weed interferes with management and can outcompete native vegetation. It is a serious weed in rice and shows allelopathic activity, negatively affecting growth and development of other plant species. The weed is a secondary host of pest and diseases such as rice earhead bug (Leptocorisa acuta), paddy armyworm (Mythimna separate), rice sheath blight (Rhizoctonia solani).