Parthenium hysterophorus is

Correct option is A

✅ (a) C3 and C4 plants
· Parthenium hysterophorus is primarily a C3 plant but under certain stress conditions, it exhibits C4-like traits.
· Some literature classifies it as a C3-C4 intermediate species.
· Its photosynthetic flexibility enables it to thrive in various environmental conditions.
❌ (b) CAM plant
· CAM (Crassulacean Acid Metabolism) plants fix CO2 at night; Parthenium hysterophorus does not follow CAM pathway.
· Hence incorrect.
❌ (c) C3 plant
· While it is mainly a C3 plant, the question’s emphasis on duality makes option (a) more accurate.
· Selecting only C3 misses the C3-C4 intermediate aspect.
❌ (d) C4 plant
· It does not exhibit full-fledged C4 photosynthesis like maize or sugarcane.
· Incorrect classification.