Diagnostic key to the species of Lychnophora from Distrito Federal and Goiás State

1. Leaf blade deltoid to ovate; one floret per head ................................................................................................................... L. goiana

– Leaf blade linear, narrowly elliptic, oblanceolate, spatulate or lanceolate; 3–9 florets per head.......................................................2

2. Leaf adaxial surface glaucous; phyllaries weakly imbricate, deciduous......................................................................... L. planaltina

– Leaf adaxial surface never glaucous; phyllaries imbricate, persistent ...............................................................................................3

3. Leaf with midvein enlarged basally on abaxial surface; involucre campanulate; cypsela sparsely strigose ................. L. salicifolia

– Leaf with midvein not enlarged basally on abaxial surface; involucre cylindrical; cypsela glabrous .............................. L. ericoides