calamondin

(kălˌə-mŏnˈdĭn)

1. A small evergreen citrus tree (ˣCitrofortunella mitis), widely cultivated as a houseplant for its glossy foliage and ornamental fruits.
2. The sour fruit of this plant, resembling a small tangerine and sometimes used as a flavoring or for beverages, sauces, or marmalades.