Question

Congress grass is
A. Cynodon dactylon
B. Digitaria purpurea
C. Cymbopogon Citratus
D. Parthenium hysterophorus

Answer 1

Hint: This grass is also known as gajarghans or carrot grass in India. In America, this grass is popularly known as white herb weed, famine weed, etc.

Complete Answer:
Congress grass is a flowering plant in the Aster family. It is endemic to the American tropics. Popular names include Santa Maria, Santa Maria Feverfew, white herb weed, and famine weed. It is locally known in India as carrot grass or Gajar Ghans.
The pollen grains of congress grass enter disturbed ground, including roadsides. It infests pastures and crops, sometimes causing catastrophic yield losses, as evidenced in common names such as famine weeds.
Extreme outbreaks have been ubiquitous in certain regions, impacting livestock and crop production and human health. It first identified as an invader to be a contaminant in imported wheat. The plant develops allelopathic chemicals that kill crop and pasture plants and allergens that influence both humans and livestock. It often also causes allergy from pollen.
A) Cynodon dactylon is known as Indian doab, ethana grass, dubo, Bermuda grass, Bahama grass, durva grass, devil's grass, couch grass, arugampul, Dhoob, grama, wiregrass, dog's tooth grass, scutch grass, etc. This grass is local to the eastern hemisphere.

B) Cymbopogon citratus is popularly known as lemon grass. This grass is a tropical plant local to Maritime SouthEast Asia and has been spread to many tropical regions.

C) The botanical name of congress grass is Parthenium hysterophorus. This grass is native to American tropics.

Thus, the correct answer is option D i.e., Parthenium hysterophorus.

Note: Parthenium hysterophorus is called carrot grass as it looks similar to the carrot plants at the stage of seedling. This grass is used in traditional treatment of fever, dysentery, diarrhea, malaria, urinary tract infection, etc.