The sepals of this Nervilia crociformis flower are fleshy, yellowish green to lemon with glistening surface cells and faint longitudinal veins in the photo.
The median sepal is below, the conspicuous white lip of the non-resupinate flower at the top, over the purple column parts. The yellow band up the lip surface among the fleshy finger-like protrusions is short in the flower in picture (Leistner, (Ed.), 2000; iNaturalist; Wikipedia; www.africanorchids.dk).