About this variety
The name is so familiar that most people have stopped thinking of it as a variety at all. Cayenne is the orange-red powder in the spice rack and the yardstick most cooks measure their tolerance against. It is also a specific old cultivar, and it remains the most quietly useful hot chilli you can grow here.
The pods are long, slim, slightly curved and tapered to a point, running 10 to 25cm and ripening glossy green to bright scarlet. That size is unusual among the hot chillies, and a mature plant will carry dozens in a decent summer. The heat sits at 30,000 to 50,000 Scoville units, about ten times a jalapeno, which is where most home cooks and sauce makers want to live.
The flavour is the one you already know: sharp, clean, peppery and direct, with a bright acid finish. No smoke, no sweetness, no fruity complication. That plainness is the point. It is a Capsicum annuum, so it is a bushy 60 to 120cm and far quicker and less temperamental than the superhots. If you grow only one hot chilli, this is the sensible choice, and the thin pods dry and grind into your own cayenne.