The chile de arbol is pronounced: cheel ay day ar boll. Chiles de arbol are narrow, curved chilli's that start out green and mature to bright red. The arbol chile is very hot, and related to cayenne pepper. Be careful during preparation.
Chile de árbol (Spanish for tree chili) is a small but potent Mexican chili pepper, a variety of of species Capsicum annuum. It is known as bird's beak chile and rat's tail chilli
Chile de árbol has heat index of 15,000 to 30,000 SHU (Scoville Heat Unit). It is 5-8 cm long and 0.5-1 cm in diameter, with a curve. The pepper is green, maturing to a bright red, and stays bright red when dried.
Chile de árbol can be found fresh, dried, or powdered, and often used in table sauces, soups, and stew. Whole peppers are used to flavor oils and vinegars. In powdered form, it is great in soups and chilis (for extra heat). Dried peppers are often used to decorate wreath.