Quite often I am sending e-mails about medical herbs/spices.
I am not a botanist, but I think it would be good to understand the minimum about the nomenclature [how plants are given a name]
Every plant has a unique name in Latin.[all over the world the same name]
Latin is a “dead” language so there is no danger that the names will be changed by language development.
I recently sent you an article about: Nepeta cataria [ good for children]
Nepeta cataria is also known as catnip by most people but there maybe many names for this plant.
Example: Nepeta cataria, commonly known as catnip, catswort, or catmint” Urdu: Badranj boya
So Latin was chosen to know all over the world about which plant we are talking.
Nepeta: The first name is the genus should always be written with a capital letter].
But there are many nepeta sorts[species] so the second name [the species[ is cataria [not starting with a capital letter] and this tells us which plant we are talking about.

I most herbal you will see that also both the genus and the species are always Italicized
and this is the correct way to do it.
I may not always follow the rules because I may forget [ remember , I am not a botanist, so forgive me]

Another example :Chamomile……….the most well known sorts are German Chamomile= Matricaria recutita or Chamomille recutitia and Roman Chamomile=Chamaemelum nobile or Anthemis nobilis

If you look at the Web you see that not always is indicated what is being is sold:so PAY ATTENTION AT WHAT YOU WANT TO BUY

Chamomile flower [HERBPHARM
(Matricaria chamomilla) (O) (F) extract This Matricaria recutita ClEARLY INDICATED

Chamomile (flower)
Chamomile Extract (flower) standardized to 1.2% apigenin (3.0 mg)
250 mg
To stay at home[Israel]
   Silybum marianum שם מדעי
  Our Lady’s Thistle, Holy Thistle, Milk Thistle גדילן מצויCommon name

Hope this story was not too complicated!

So if you buy a herb check if both names are written : the genus and the species