At first glance, it looks harmless. Standing two to three feet tall with lush green leaves and clusters of tiny white flowers, the plant resembles coriander. But beneath its innocent appearance lies a growing threat to agriculture, public health and livestock.

Parthenium (Parthenium hysterophorus), one of the world’s most invasive and toxic weeds, is spreading rapidly across Chuadanga, prompting concern among farmers, agricultural scientists and health experts. 

They warn that failure to contain it now could have serious long-term consequences.

Field visits and local inquiries found the weed spreading across all four upazilas of the district—Chuadanga Sadar, Alamdanga, Damurhuda and Jibannagar. 

It is increasingly visible along roadsides, railway tracks, fallow land, border areas and even around cropland. 

Yet most residents remain unaware of the plant’s identity or the dangers it poses.

Originally native to North and South America, parthenium is believed to have entered Bangladesh through neighbouring India before gradually expanding across different regions. 

Despite its relatively short life cycle of just three to four months, a single plant can produce thousands of seeds several times during its lifespan. 

The seeds are easily dispersed by wind, rainwater, vehicles and animals, allowing the weed to colonise new areas rapidly.

Farmers said the plant has become noticeably more common over the past few years.

Lutfar Hossain, a farmer from Hogaldanga village in Damurhuda upazila, said the weed was rarely seen in the area a few years ago. “Now it is growing around many crop fields, and we are seeing its impact on crop growth,” he said.

Another farmer, Zainal Ali of Mominpur in Chuadanga Sadar, said the weed has spread around agricultural land in his village. “We are worried because it is spreading quickly. Cattle and goats sometimes eat it. It needs to be controlled before the situation gets worse,” he said.

Agricultural experts warn that parthenium not only competes with crops for space but also absorbs vital soil nutrients and releases chemicals that suppress the growth of surrounding plants. 

Studies suggest the weed can reduce crop yields by as much as 30 to 40 percent, particularly affecting mango orchards, sugarcane, banana, turmeric, bitter gourd, beans and various vegetable crops.

Health specialists also caution that the weed poses significant risks to humans.

Former Chuadanga Civil Surgeon Dr Hadi Zia Uddin said contact with parthenium can trigger allergic reactions, skin diseases, itching, eye irritation and respiratory problems.

“The leaves, flowers and pollen are all harmful. Airborne pollen can enter the lungs through breathing and may create long-term health complications. Public awareness is essential to reduce exposure,” he said.

The threat extends to livestock as well.

Chuadanga District Livestock Officer Dr Md Shahabuddin said animals that consume the weed may suffer from digestive disorders, fever, weakness and other health complications. Lactating dairy cows are particularly vulnerable, he added.

Faruk Hossain, assistant professor of botany at Chuadanga Government College, described parthenium as a highly invasive species whose leaves, flowers and seeds all contain toxic substances.

“Its seeds spread easily through the wind, while its pollen can enter the human respiratory system. Without timely intervention, its expansion could become far more difficult to control,” said.

Masudur Rahman Sarkar, deputy director of the Department of Agricultural Extension in Chuadanga, said the government has identified parthenium as a toxic invasive weed and is aware of its harmful impacts.

“The weed depletes soil nutrients and inhibits the growth of nearby plants. We are advising farmers on identification and management practices to limit its spread,” he said.