Capsicum annuum var. glabriusculum

Capsicum annuum var. glabriusculum, a chili-pepper variety of Capsicum annuum, is native to southern North America and northern South America. Common names include chiltepín, Indian pepper, grove pepper, chiltepe, and chile tepín, as well as turkey, bird’s eye, or simply bird peppers (due to their consumption and spread by wild birds; "unlike humans birds are impervious to the heat of peppers"). Tepín is derived from a Nahuatl word meaning "flea". This variety is the most likely progenitor of the domesticated C. annuum var. annuum. Another similar-sized pepper, 'Pequin' (also called 'piquin') is often confused with tepin, although the tepin fruit is round to oval where as the pequin's fruit is oval with a point, and the leaves, stems and plant structures are very different on each plant....read more on Wikipedia.