Which plants cause weakness or paralysis due to neurotoxicity?

• A. Coffee Senna and Sicklepod (Cassia)
• B. Deadly Amanita and Death Angel (Amanita)
• C. Nettle and Stinging Nettle (Urtica)
• D. Guajillo (Acacia), Coyotillo (Karwinskia), Vetchling + Wild Pea + Singletary Peak (Lathyrus), Sorghum + Sudan Grass + Milo + Johnson Grass (Sorghum)

Answer: (D)

Neurotoxicity from plants causes weakness or paralysis when the toxins interfere with nerve function or neuronal metabolism. Among commonly encountered toxic plants, certain species are well known for producing progressive neurological weakness or paralysis.

Grass peas of the Lathyrus genus contain a toxin called β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP) that injures motor neurons, producing lathyrism with gradual weakness and spastic paralysis of the hind limbs. Coyotillo, from the Karwinskia group, carries toxins that damage peripheral nerves, leading to weakness and paralysis. Some Sorghum group plants can carry cyanogenic glycosides that release hydrogen cyanide when the plant is stressed or damaged; this can cause rapid systemic weakness and, with sufficient exposure, paralysis due to cellular hypoxia.

Putting those together, this set includes plants with well-documented neurotoxic effects resulting in weakness or paralysis, making it the best match. The other options involve plants that cause primarily gastrointestinal effects, dermatitis, or non-neurological toxic outcomes, and thus do not fit the pattern of neurotoxic weakness or paralysis as their hallmark.