Botanist quickly found Latin lacked words they needed to describe the parts of a plant, the Romans having never seen any need to do such things, so they modified the language for their own needs. The school Latin you may have learnt  has evolved considerably since the Romans; to the point a Roman would hardly recognise it. This has lead to Botanical Latin, which has branched off from ‘School Latin’, and has developed its own means for words and grammar. Anyone wanting to learn more would do well to look at Botanical Latin by William T. Stearns which is the standard text on the subject. Its very heavy going though!