Holothrix secunda flower

At close range a Holothrix secunda flower discloses a small, whitish, here translucent membrane. It is the bract covering the basal part of the ovary, before the part of that ridged body that curves down. Three whitish green sepals lie on the petal bases, less than 4 mm long, 2 mm wide and inconspicuous.

The lip consisting of five fleshy, curving lobes is positioned below the two lateral petals that appear similar to them, but point up. The lip is actually the third petal of this orchid. The three petals form the inner whorl of floral segments, the three sepals make up the outer whorl. In this Holothrix these lateral petals are attached to the lip at its base.

The fact that the lip is positioned below the flower mouth here as in many orchids indicates that the flower is resupinate. This means that the bud had twisted round through a semi-circle as the lip was originally at the top of the flower structure.

Orchid lips positioned below the flower mouths offer insect landing sites, helpful in pollination visits. Whether it makes much difference in Holothrix is not known. Holothrix pollinators are often moths (Liltved and Johnson, 2012; Vlok and Schutte-Vlok, 2015; iNaturalist).