| At the time of the last revision of the genus, Apios americana Medikus was the only described North American species and none of its six infraspecific taxa had been described. |
| Several researchers recognize the strength and reproducibility of this method at the infraspecific level. |
| Perhaps Furlow lacked the quantity of data needed to resolve the infraspecific variation that exists. |
| Thus we considered the number of lateral costae in S.7 spiriferformis to be within the infraspecific variation of Sinostricklandiella robusta. |
| This nomenclator contains all specific and infraspecific names attributed to the suborder. |
| The Asian species are represented by three specific and two infraspecific taxa. |
