Cotyledon tomentosa subsp. tomentosa flowers open and closed

The outside surfaces of Cotyledon tomentosa subspecies tomentosa flowers are hairy. When open the five tips recurve elegantly, exposing anthers and stigmas in the flower mouth to pollinators. When that happy period is over, the petals clamp shut and turn brown as the juices leave the outer floral components, getting busy deeper inside and out of sight (Smith, et al, 2017; iNaturalist; Wikipedia).