Pterygodium nigrescens, one of many grassland orchids

This Pterygodium nigrescens inflorescence was photographed in northern KwaZulu-Natal grassland. The tubers survive grass fires, but flowering is not dependent upon fire.

The flowers secrete small quantities of floral oil, collected by bees of the Rediviva genus. In habitats of the plant’s distribution where these bees do not occur, such as fynbos in the south, self-pollination solves the problem.

In evolution a problem is solved by natural intraspecies differences generating various forms, some of which being compatible with prevailing or emerging conditions, or the whole species disappears.This  is followed by natural selection, i.e. the discarding of all inappropriate varieties via death before setting seed, the ”failed experiments" from maximal procreative activity. The survivors are the ones best suited to the prevailing conditions, the adapted new extant generation, the others becoming extinct.

The roots of this plant have been used by indigenous populations to concoct infusions for warding off evil; flower colour and shape probably suggesting unusual powers to superstitious minds in the prescientific era (Liltved and Johnson, 2012; Pooley, 1998).