No.
Okay, guys, here's the deal about marshmallow leaf. It was one of the "special herbs" you found in stuff like K2 and Spice, along with damiana and a few other things. Those have been banned because people were smoking them to get high, as we know, so now all these guys who have hundreds of pounds of marshmallow and damiana leaf they can't get rid of are promoting them as the Special Magical Ingredient in K2. Wrong--the synthetic cannabinoid JWH-018 the marshmallow and damiana leaves were spiked with was the Special Magical Ingredient.
Marshmallow is a "healing herb" in that it will cure sore throat and dry cough if you make tea out of it, and they don't test just for marshmallow leaf, but if you smoke it you are NOT going to get high so don't bother.
Pretty much anything can be detected in a drug test.
no
Yes, but it requires a specific test in order to be detected.
a urinalysis does not test for drugs it only tests for urinary tract infections
urine test
Yes.
Depends on the drug and the type of test.
It cannot be detected in any drug screening. :) There is no test that can detect it.
Yes.
Yes
Not in my experiences ;)
nope