Detect Poison and Disease (R)

(a yew leaf)
For the duration, you can sense the presence and
location of poisons, poisonous creatures, and
diseases within 30 feet of you. You also identify
the kind of poison, poisonous creature, or disease
in each case.
The spell can penetrate most barriers, but is
blocked by 1 foot of stone, 1 inch of common
metal, a thin sheet of lead, or 3 feet of
wood or dirt.