In a conversation recently with a friend at Palo Alto’s Gamble Garden, he told me about a plant familiar to him from Mexico, which turned out to be Roselle. From Wikipedia:
Roselle (Hibiscus sabdariffa) is a species of Hibiscus native to West Africa, used for the production of bast fibre and as an infusion, in which it may also be known as carcade. It is an annual or perennial herb or woody-based subshrub, growing to 2–2.5 m (7–8 ft) tall.
A stem of Hibiscus sabdariffa showing flower, calyx and leaves, at Wave Hill, the Bronx