Xylonagra arborea is a flowering plant endemic to the western side of the Baja California Peninsula.

It has bright red flowers, alternate small leaves, and blooms from February to October, or possibly year-round in the event of ample rainfall.

The floral tube is scarlet, and about 2 cm long, widening upwards near the middle.

[3] This species was once within the genus Hauya, but John Donnell Smith and Joseph Nelson Rose split it from the genus and into Xylonagra on the basis of a smaller size, pubescent inner floral tube and the xerophytic character of Xylonagra plants.

There are two subspecies of Xylonagra arborea:[3] This genus is endemic to the Baja California Peninsula in Mexico.