Disa sagittalis flower

The white, cream or pale mauve flowers of Disa sagittalis may have some vivid colouring upon their petals, i.e. both on the pair of lateral petals and the lip. Although not the largest segments of this corolla, the arrow-pointed, erect, lateral petals gave the species its name: sagittalis being derived from the Latin sagitta meaning arrow and -alis meaning resembling or pertaining to.

These two petals grow from a broad, joined base that spreads around the stigma. Dark longitudinal lines, or only rows of dots on or near the margins, may occur on a lateral petal.

The dorsal sepal is largest of the six corolla segments. It has a slightly concave middle section over the flower centre, while its lateral lobes, forming a somewhat T-shape, are rounded and reflexed on the side, unlike many disas that have the sides of the dorsal sepal folding in over the petals. 

There is a curious difference between the dorsal sepal shape of the flower in picture, compared to that of the cream flower also shown in this Album. The lateral lobes seen here are free and erect like white Mickey Mouse ears, while the other has a continuous fringe along a margin that curves in a semi-cylindrical way to the sides. This may reflect a misidentification in the case of one of the two specimens. The available literature does not speak of a cream flower colour.

Flower diameter is about 2,5 cm (Liltved and Johnson, 2012; Pooley, 1998).