I had never heard of the morro seed, until I asked my mother-in-law how to make horchata, a milky-looking drink that my husband is quite fond of. My suegra sweetly replied that I would simply need to find myself some, "semilla de morro".
The morro seed comes from a large, coconut sized, lime-colored fruit that grows on the morro tree. The seeds are dried and crushed up into a very fine powder so that they can be used to make horchata salvadorena. To make horchata salvadorena, the morro seed powder is combined with a mixture of ground up rice and milk, nuts, and an array of spices such as cinnamon, cocoa, nutmeg, and vanilla.