The dorsal sepal at the top of the Pterygodium nigrescens flower is pale in this case. Minute brown, green and shiny spots make up but some of its colours. Nearly round, this sepal is about 3 mm long and nearly as wide. The lateral petals flank it, showing only curved strips to the camera. Some lip parts are dully obscured below (Liltved and Johnson, 2012; Manning, 2009; Pooley, 1998; iNaturalist).