The jalapeño is variously named as huachinango and chile gordo in Mexico. The cuaresmeño closely resembles the jalapeño; its seeds have the heat of a jalapeño, but the flesh has a mild flavor close to a green bell pepper.
The name jalapeño is of Spanish origin. The Spanish suffix -eño signifies that the noun originates in the place modified by the suffix, similar to the English -(i)an. The jalapeño is named after the Mexican town of Xalapa (also spelled Jalapa). Xalapa is itself of Nahuatl derivation, formed from roots xālli/ˈʃaːlːi/ "sand" and āpan/ˈaːpan/ "water place."
As of 1999[update], 5,500 acres (22 km2) in the United States were dedicated to the cultivation of jalapeños. Most jalapeños are produced in southern New Mexico and West Texas.
Jalapeños are a pod type of capsicum. The growing period is 70–80 days. When mature, the plant stands 70–90 cm (28–35 in) long tall. Typically, a plant produces 25 to 35 pods. During a growing period, a plant will be picked multiple times. As the growing season ends, the peppers turn red. Jalapeños thrive in a number of soil types and temperatures, provided they have adequate water. Once picked, individual peppers may turn to red of their own accord. The peppers can be eaten green or red.
Compared to other chillies, the jalapeño heat level varies from mild to hot depending on cultivation and preparation and can have between 2,500 and 10,000 Scoville units. The majority of the capsaicin and related compounds are concentrated in the placenta membrane surrounding the seeds. If fresh chili peppers come in contact with the skin, eyes, lips or other membranes, irritation can occur; some people who are particularly sensitive wear latex or vinyl gloves while handling peppers.
Halfway ripe jalapeño in a planter box in New Jersey in September
A jalapeño plant with pods. The purple strips on the stem are anthocyanin, due to the growth under blue-green spectrum fluorescent lighting