This is the best comparative chart on cannabis taxes I’ve seen, from an 800-person law firm. The big accounting firms were still steering clear of marijuana, last I heard, and this is the biggest law firm I’ve heard of.
It glosses over the way Nevada always taxes by weight. https://newrevenue.org/2017/07/02/nevadas-70-cent-per-gram-tax-on-marijuana-flower/
And it glosses over the way Colorado often taxes by weight. https://newrevenue.org/2017/07/23/is-colorados-new-marijuana-tax-leaky/
I haven’t read the whole thing, but I haven’t found any other problems so far.
UPDATE: Louisiana’s sales tax will apply to medical cannabis, we learn after publication of the chart, which reported it as “unclear.” http://www.theadvocate.com/baton_rouge/news/business/article_504d1b92-6f24-11e8-94c2-5bd6afda20a5.html. And, unlike the chart, I don’t see an argument that Louisiana excise tax will apply.
On CNR site: Cannabis-Industry-State-Tax-Guide