Entry From
Flora of North America, Vol 8,
Discussion
The treatment presented here is based on the morphological and molecular analyses of P. W. Fritsch (1996, 1997).
The only subspecies of Styrax platanifolius to occur outside the flora area is subsp. mollis P. W. Fritsch, from Nuevo León and Tamaulipas, Mexico. It grows in wooded canyons along the eastern escarpment of the Sierra Madre Oriental. All five subspecies are narrow endemics; of the four subspecies in the flora, three (subspp. platanifolius, stellatus, and texanus) occur only in the Edwards Plateau region of Texas; the fourth (subsp. youngiae) is known only from the Davis Mountains of western Texas and from northern Coahuila, Mexico.