Red Fresno peppers are similar to the jalapeno pepper, but they contain thinner walls.  The Fresno pepper starts out bright green, then changes to orange and red as it matures.  In cooking, it can be substituted for jalapeno or Serrano peppers.  It is an excellent accompaniment to rice and black bean dishes.  Fresno peppers provide high levels of vitamin C and the B vitamins, and contain significant amounts of iron, thiamin, niacin, magnesium, and riboflavin.