I think Eric (Eric in SF@Flickr) has outdone himself with this photograph (no small accomplishment!) (original | BPotD Flickr Group Pool). It is so very welcome to have some colour when the days are starting to turn grey. Thank you, Eric.
Like many of the other solanaceous plants we eat, Capsicum has its origins in Central and South America. Being more specific is difficult, because of domestication of the wild plant, a topic eloquently covered in Eshbaugh’s Peppers: History and Exploitation of a Serendipitous New Crop Discovery (the paper also includes a detailed discussion of the taxonomy).
As is usual with food plants, Purdue University’s Center for New Crops and Plant Products has an excellent factsheet with details on economic botany, the chemistry of capsaicinoids (what makes ’em hot!) and a description of the plant.
Wikipedia is also worth investigating; it has a list of cultivars, as well as an explanation of why I didn’t attempt to share a common name (scroll down the page) for the international audience that reads BPotD.
Botany / horticulture resource link: I haven’t read the paper yet, but the abstract has me intrigued: The Horticultural Trade and Ornamental Plant Invasions in Britain by Dehnen-Schmutz et al. in an upcoming issue of Conservation Biology.