Is bissap the same as sorrel?

It is called bissap in Senegal, where the sweetened juice is a common drink with meals, served as karkanji in Chad, with ice, ginger and spices, and in Tanzania I have bought packets of dried hibiscus flowers labeled rosella. It’s also popular as sorrel in the Caribbean, which of course shares a culinary heritage with Africa. Because of its powerful tang it is hard to drink more than a glass of bissap juice unless diluted with extra water, and it is often heavily sweetened with sugar or honey. Inspired by the ice lollies, I have devised a recipe for bissap sorbet. It is magnificent in colour, and will certainly bring spectacle to any meal.