What is the taxonomic rank of $Rhizobium$?

Assertion $(A)$: The nomenclature of organisms should be done in the Latin language.
Reason $(R)$: In nomenclature,the first name should be the species and the second name should be the genus.

$A$ group of orders is called........

In botanical nomenclature of plants:

The term species was coined by

In plant taxonomy, the taxonomic category 'Order' generally ends with which suffix?