Which of the following scientists classified plants into groups based on their habitat?

The scientific name of zebu (cattle) is

The scientific name of Sunflower is:

Through the study of classification,which of the following is true?

What is binomial nomenclature?

$Nicotiana$ $sylvestris$ flowers only during long days,while $N.$ $tobacum$ flowers only during short days. If raised in the laboratory under different photoperiods,they can be induced to flower at the same time and can be cross-fertilized to produce self-fertile offspring.
What is the best reason for considering $N.$ $sylvestris$ and $N.$ $tobacum$ to be separate species?