It turns out that I wasn't that far off base. Calamansi citrus are actually a very old cross between mandarin oranges and kumquats. The fruit is grown throughout Southeast Asia, primarily in the Philippines and Malaysia, but cultivation has gradually spread to other warm growing regions - like California! The growers at my farmers market called them lemons, but you might also find them referred to as Calamansi limes, Chinese oranges, kalamansi, golden limes, or even Panama oranges.
Calamansi is one of those ingredients that makes Filipino and Malaysian dishes taste truly authentic. The flavor is something like a sour orange or a slightly sweeter lime, and it has a fragrance to match. It gets added to sambals and laksas, squeezed over freshly-steamed fish, or even sipped on its own as a refreshing drink.
If you get your hands on some calamansi, try out these recipes:
Do you know and love calamansi citrus? How do you use it?
(Images: Emma Christensen)