Key to the species of Parahellenia in Vietnam

1. Leaf blade puberulent abaxially; labellum cream white...................................................................................................... P. candida

- Leaf blade glabrous; labellum yellow with longitudinal orange to red markings at center...............................................................2

2. Plants unbranched or barely branched; bract apex with a soft mucro............................................................................. P. trongduyii

- Plants densely branched; bract apex with a sharp mucro............................................................................................... P. tonkinensis