Rachel Laudan

“Salvadorans are fiercely loyal to their horchata, made from the seeds of morro, a green, hard-shelled fruit that looks like a coconut. . . .

The morro grows on a wide-branched tree, part of the calabash family. The small, gourdlike fruit stands out because it is attached directly to the tree’s trunk and branches. For farming families, morro trees were a prominent part of the landscape.

The black, lentil-shaped seeds are the tree’s coveted treasure. Pried from the fruit’s pulp, “they are put in the sun to dry and then they’re ready to be ground,” Velasquez says. The resulting powder is blended with water to make horchata.”

Here’s the link to full article by Joel Denker in the Washington Post.  And here’s a description of morro (Crescentia alata).