Andean stimulant

COCA

This plant's leaves are traditionally chewed in South America to combat altitude sickness and fatigue. It's also the source of a well-known alkaloid used in medicine.

Andean stimulant" points to coca, the plant native to the Andes whose leaves are chewed or brewed for their mild stimulating effects. It’s been used for centuries in South American cultures to combat altitude sickness and fatigue. The clue avoids the more famous derivative (cocaine) to focus on the natural plant itself, keeping it straightforward.