Why are flora given Latin names when they're far harder to remember? Is it down to pretentiousness, or is there a more practical reason?

Answer 1

Many organisms are given Latin names by the scientific community to be more specific; although you are specifically discussing plants, I am going to use elephants as an example.

What we refer to as "elephants" are actually two different species; colloquially, we often refer to them as African elephants or Indian elephants when we need to make the distinction, but usually we just call them elephants. And in most cases, that is all you need to identify the animal. Scientists, however, need to make sure that everybody is on the same page when they are discussing these elephants despite the fact that the scientific community speaks many languages. For this reason, we have turned to Latin to give the "scientific names" for organisms.

Same thing exists with plants; in fact, all living organisms, from the smallest bacteria to even human beings, have a scientific name that is in Latin. In some instances, this Latin name becomes commonly used; for example, everybody knows that modern humans are "homo sapiens." Without knowing the specific background to your question, I would guess either the Latin names became commonplace for the plants you are talking about, or the setting you are referring to requires (at least for a large contingent of the community) enough specificity in species that the Latin names are required.