How do species relate to spices?

I find it interesting when I discover that similar-sounding words that seem to have unrelated meanings actually are related etymologically.

This week, when I was reading my newly purchased book, Herbs and Spices; the Cook's Reference, by Jill Norman, I discovered the relationship between the words specie, spice and species.

On page 9 she writes this about the word spices:

Again our word derives from Latin, where species meant specific kind but, in later use, goods or merchandise - spices certainly being an important commodity even at the time of the Romans.

This made me wonder about the expression payment in specie. I didn't know what it means, but I've read it in historical novels.

Dictionary.com says of the word specie:

noun

1.

coined money; coin.

Idioms

2.

in specie,

1. in the same kind.
2. (of money) in coin.
3. in a similar manner; in kind:
   Such treachery should be repaid in specie.
4. Law. in the identical shape, form, etc., as specified.

Collins English dictionary gives the origin of the phrase in specie as:
C16: from the Latin phrase in speciē in kind
Ref: http://dictionary.reference.com/browse/specie