Hi Kristen,
When shopping for plants, there are some somewhat obscure things to keep in mind:
The plants may be labeled incorrectly. If they have plastic label sticks inserted into the dirt - these can easily fall out and may be stuck in another pot. I cannot tell you how many times I have seen this in the plant departments - especially in the small plant section (2" and 4" plants). If in doubt - ask the plant department personnel.
Consider what you are buying the plant for. If the plant isn't going to be eaten, or the sap ingested, there isn't the strict concern for worry about toxicity. If the plant goes into a vivarium for pygmy chams - the need is to provide a walkway (ivy and other creepers); a tall sleeping place (your miniature scheffy); or color contrast.
I really wouldn't hesitate using either of the plants you found in your pygmy tank.
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