Chile de arbol are long, red, slender very hot chiles used in Mexican cooking. De arbol chiles are available fresh, dried and in powdered form. Also referred to as simply arbol chiles and are used in sauces and fresh salsa dishes.
One of our favorite salsas combine arbol chiles, guajillo chiles and peanuts, aka. salsa de cacahuate y chile arbol y guajillo. I love this on tacos and even a dip for fresh vegetables. It is pretty hot so be advised.
On a scale of 1 - 10 the arbol chile is about a 7.5. On the Scoville heat scale it is between 15,000 to 30,000.
If you don't have de arbol chiles you can easily substitute red pepper flakes which are primarily cayenne chiles. 1/4 to 1/2 teaspoon would be equal to about 1 whole arbol chile. Alternatively you may want to substitute equal amounts of of either of these hot chiles:
OR>Thai chiles OR> Chiles Japones OR> Chile Tepin OR> Chile Piquin