The rapid growth of suspected Parthenium plants along stretches of National Highway-27 in Assam’s Bajali district has raised concerns over public health, biodiversity loss, and environmental degradation.

About Invasive Alien Species (IAS)

• They are non-native species that establish, spread rapidly and cause ecological, economic or health damage.
• The Convention on Biological Diversity (CBD) defines invasive alien species (IAS) as those whose introduction and spread outside their natural distribution threaten biodiversity.
• IAS can include animals, plants, fungi, and microorganisms, affecting various ecosystems.
• India’s efforts to manage IAS are guided by the Biological Diversity Act, 2002, National Biodiversity Action Plan, and the Kunming-Montreal Global Biodiversity Framework (Target 6), which aims to reduce invasive species globally.

What is Parthenium?

• Parthenium hysterophorus, commonly known as Congress Grass, Carrot Weed, or White Top, is one of the world’s most harmful invasive alien plant species.
• Parthenium hysterophorus is an herbaceous, erect, annual plant.
• It is a poisonous, pernicious, problematic, allergic, and aggressive weed posing a serious threat to human beings and livestock.
• It is native to Central and South America and belongs to the family Asteracae (compositae).
• It was accidentally introduced into India during the 1950s through contaminated grain imports.
• A single plant can produce thousands of seeds.
• Seeds are dispersed through: wind, water, vehicles, road networks, contaminated soil and agricultural products.
• Highways and railway corridors often become major pathways for its spread.

Parthenium as Concern

• Public Health Impacts
  • It can cause allergic dermatitis, skin rashes, and itching.
  • It may trigger asthma, bronchitis, and respiratory disorders.
  • Continuous exposure can lead to chronic allergic reactions.
• Ecological Impacts
  • It is an invasive alien species that spreads aggressively.
  • It suppresses the growth of native grasses and plants through allelopathy (release of harmful chemicals).
  • It reduces biodiversity and alters ecosystem balance.
  • It affects grazing lands and lowers fodder availability for livestock.
• Agricultural Impacts
  • It reduces crop productivity.
  • It contaminates agricultural fields and pasture lands.
  • It increases management costs for farmers.

Other Invasive Alien Species  in India

Exam Hook: Prelims Question

Consider the following statements regarding Parthenium hysterophorus:

1. It is an invasive alien plant species in India.
2. It can cause allergic and respiratory disorders in humans.
3. It enhances biodiversity by supporting native grasses.

Which of the statements given above are correct?

(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Answer: (a) 1 and 2 only

One-Line Wrap

Parthenium is a highly invasive alien weed that threatens biodiversity, agriculture, and human health, making its early detection and control crucial for ecological security.