The Jalapeno is one of the best known chile peppers and is most widely used chile pepper in the United States. It is a thick-fleshed pepper with a hot green vegetable flavor.
The Jalapeno Chile is named after the city of Xalapa [Jalapa] in the state of Veracruz in Mexico, and appears in all sorts of Latin cooking, because of its spicy-but-not-too-hot flavor. The use of the Jalapeno chile dates all the way back to the Aztecs.
On the mild end of the hot pepper spectrum, Jalapeno chiles have 2,500 - 8,000 Scoville heat units. [By point of comparison, Habanero Chiles, at the other end of the spectrum weigh in at a face-melting 100K - 300K Scoville units]. The Jalapeno chile's flavor is akin to a lightly hot bell pepper. The dried Jalapeno chile is a Chipotle Chile.
Use Jalapeno chile in eggs, salsa, cornbread and other corn dishes, and in jambalaya, soups and stews.
Little-known fact: In 1982, Jalapeno chiles were the first chiles to be taken into space.