Try this forum, might be more relevant.

Here is a link that might be useful: Deer Resistance

The family of Scrophulariaceae has many members, one of them, like the foxglove (Digitalis purpurea), have digitoxin produced from the leaves.

Digitoxin is a bitter white glycoside used as a heart stimulant.

For the senna plants, especially the genus of Cassia, yield tanbark used in preparing leather.

Tanbark is the tree bark used as tannin.

P/s: Some said that foxglove now is being treated under the family of 'Plantaginaceae'.

Aminbest

Thanks for the info. I was unaware that Digitalis was in the Scrophulariaceae. Interesting on the Cassia. Considering it's deer repellency and bold nature, I'll have to plant more of it!!

Sorry Resin, I don't see where the forum for difficult places has anything to do with the botany of why certain plants are toxic to certain animal species...Just moving the post down the road?

Fred

You're welcome, anytime.
Feel great to find right place to talk about botany.

"Sorry Resin, I don't see where the forum for difficult places has anything to do with the botany of why certain plants are toxic to certain animal species...Just moving the post down the road?"

Hi Fred - I thought the forum listed 'Deer resistance' in the forums index might be a better place to try, after seeing no responses here for over a month. This forum doesn't seem to move very fast!

Resin

Resin, I know what you mean...I used to hang out a lot at the bog garden forum but it moves slower than the continents most of the time, unlike the forums that you often hang out at. Conifers and Trees, etc. those are frequently much more interesting.

Problem with the Difficult places forum is, deer here are so bad the advice there is worthless here. They eat things that are supposed to be inedible to them, Ferns, Ginkgo, Convovulus, even buckthorn doesn't have a prayer. Oh well, that's my bad luck!

At least you don't try to poison those deer and try alternative ways instead.

Have you fenced your precious vegetation? At least you won't get frustrated the next morning

Figuratively speaking, today's curse can be tomorrow's blessing...