Camellia sinensis is the species of plant whose leaves and leaf buds are used to produce tea.

This article could be an interesting read for you.

Don’t worry. Many people get confused with this term.
You can also refer to the Tobacconist University glossary

Some interesting material on this sensitive topic can be found here:
– Steve Saka in SocialCigar
– Cigar Press
– David Savona in Cigar Aficionado

We know, sometimes marketing messages may be confusing.
A good reference is this note from Didier V. Houvenaghel

Chemistry is complex. Here is a good read from Didier V. Hoevenaghel on the topic