In addition to P. pterotum, Krause (1913) also placed in P. sect. Platypodium four additional species, P. clementis Wright, now considered a synonym of P. fragrantissimum (a member of P. subsect. Macrolonchium); P. splitgerberi Schott, a possible synonym of P. fragrantissimum; P. lechlerianum Schott, a close relative of P. purpureoviride (a member of P. subsect. Solenosterigma); and P. ernestii Engler. Thus, of the species listed by Krause, probably only P. pterotum and P. ernestii might validly belong here. It is unlikely that P. ernestii is very closely related to P. pterotum but it does appear to be closely related to P. brunneicaule, another species placed in this section.

In addition to P. pterotum, other species of P. subsect. Platypodium that occur in Central America include: P. brunneicaule, P. copense, P. findens, and P. fortunense Croat.