Key to the Diplazium species in Rwanda

1. Fronds with gemmae at terminal pinnae; indusium attached all around the sorus (allantodioid)................................... D. humbertii

- Fronds without gemmae; indusium attached to one side of sorus (asplenioid)..................................................................................2

2. Sori up to 6–8(11) per pinnule lobe; scales only at stipe base up to 18.4 mm long, margins without trichomes ................................ .............................................................................................................................................................. D. cyamudongoense, sp. nov.

- Sori 11–23 per pinnule lobe; scales at stipe base very long, up to 20–32 mm, margins with stiff trichomes........... D. zanzibaricum