Key to the species of Platychasma Butler

1 Ground color of forewings yellow to brown; costa of forewings straight; median fascia not conspicuous; aedeagus stout, dentate ventrally ................................................................................................................... P. elegantula sp. nov

- Ground color of forewings gray to pale yellow; basal half of costa of forewings swollen outwardly; median fascia conspicuous; aedeagus slender, smooth ....................................................................................................................... 2

2 Median fascia of forewings yellow; valva bifurcate apically .......................................................................... P. flavida

- Median fascia of forewings grass green; valva with a long distal process ventrally .......................................... P. virgo