College : CMR National PU College, ITPL, Bengaluru

Sample: Parthenium hysterophorus

Site of sample collection: University of Agricultural Sciences, Bangalore

Date of Collection: 18 June 2019

Date of Observation: 21 June 2019

Students involved: Malavika Rajesh, Ramya Nambiar, , Gopika Anil, Shwetha Santhosh

Parthenium hysterophorus is a noxious weed in America, Asia, Africa and Australia. The pollen of this weed is considered to be a major allergy causing agent especially in India where it is abundantly found. Besides causing respiratory problems, P.hysterophorus has also been recorded to cause dermatitis and result in mutagenic characters in both humans and livestock.

Under the foldscope, we were able to observe the anther and pollen of the sample, both of which seemed to be brownish-yellow in colour. When observed carefully minute pollen grains can be observed which have a spiky appearance. Pollen often cause allergies when the bodies immune system considers it to be a harmful substance- like bacteria or virus and has an adverse immune response. The spiky nature of the pollen helps it cling on to objects easily and thus it can spread over a vast area.

We also got to observe a developing leaf of the plant. In P.hysterophorus the first leaves are simple, arranged in rosette and petiolated. A fully grown leaf is about 11 to 15cm in length and 6 to 10cm wide and shows pinnate venation.