Just to add two more, (depending on how many you want for your library.)

This is one of my favourite 'go-to' books whenever I want to look up a herb I'm not familiar with-

Holistic Herbal- a Safe and Practical Guide to Making and Using Herbal Remedies, by David Hoffman

https://www.amazon.com/Holistic-Herbal-Practical-Making-Remedies-ebook/dp/B00DKE9LD0/ref=sr_1_2?keywords=Holistic+herbal+hoffman&qid=1581589197&s=books&sr=1-2#customerReviews

I have a good field guide for identifying herbs in the wild, (not sure if you intend on doing this, but it's nice to be able to recognise herbs when out and about, even if you only plan on buying dried ones) but mine is for Britain and Europe. I found this one for America, and it has very good ratings-

https://www.amazon.com/Medicinal-Eastern-Central-American-Peterson/dp/0395988144/ref=sr_1_3?keywords=field+guide+to+herbs&qid=1581589555&s=books&sr=1-3