The flower of Disa uncinata is often white or cream without dark markings. A similar species also in the Disella section of the Disa genus, D. ocellata, has dark markings on its flowers. D. ocellata may, however, also have diagnostic purple-brown patches on the sides of its median sepal, as well as brownish veins across its surface, both lacking here. The margin of the median sepal is rounded at the top on the plant in picture as would be expected in D. uncinata, not pointed as in D. ocellata.
This photo was taken in Bainskloof in October when both species commence flowering (both continue until midsummer). A musty odour may be picked up from the flowers of D. uncinata (Liltved and Johnson, 2012; Vlok and Schutte-Vlok, 2015; iNaturalist; iSpot).