Disa cooperi flowers

The flowers of Disa cooperi grow densely clustered on a cylindrical spike that has a few oblong leaves scattered along the stout stalk below the flowers. An oblong green and white bract is found below every flower on the stalk. The flower faces downwards with an olive-green, spade-shaped lip below. The curving floral spur points upwards conspicuously at the back of the median or dorsal sepal. The dorsal sepal forms a rounded hood around the central floral parts, where the column is short, the anther is reflexed, the rostellum is three-lobed and the stigma is thickened. The spur is about 4 cm long, narrow and tapering towards its tip.The lateral sepals are pale pinkish in the photo.

The flowers are fragrant at night, pollinated by hawkmoths. These moths, called Basiothia schenki, have evolved the proboscis and instinctual behaviour to find the nectar hidden in the spur. The spur on the plant in picture is cream-coloured; it may also be shades of pink or reddish purple. Flowering happens from late spring through summer (JSTOR; Manning, 2009; www.tgenade.freeshell.org).