Disa chrysostachya floral details

This Disa chrysostachya flower was photographed in January. The species is deciduous and terrestrial. Some detail of the flower structure can be observed here. The densely flowered, cylindrical spike is unbranched, a Disa feature.

The flower low on the left, facing the camera, shows the curved narrow pink lip at the bottom of the flower, pointing downwards. At the top of this flower the median, upper sepal is hooded, fleshy, pale pink, semi-translucent. The smaller petals are enclosed within it. The two lateral sepals, positioned lower down on the sides are darker pink, broad and curving in with rounded tips.

During the bud phase the lip or labellum, a tepal, started off at the top of the flower, twisting down through 180˚. This phenomenon called resupination facilitates pollination in some orchids.

Looking at some of the other flowers seen from the side in the photo, the long cylindrical spurs angling obliquely downwards from the median or dorsal sepals are prominent. The sac of nectar, currency used for rewarding pollinators, is clearly visible at the end of each spur. The pollinia and stigma are in the flower centre, the pollinia at the top of the column, the yellow stigma just below it (Manning, 2009; Pooley, 998; iNaturalist; Wikipedia; www.plantzafrica.com).