The many-flowered Pterygodium hallii inflorescence becomes about 22 cm long, a dense spike. The erect bracts below the flowers are ovate and acutely tipped, 18 mm to 27 mm long and 8 mm to 14 mm wide at the base.
Some pterygodiums are resupinate, others not, while P. hallii is doubly resupinate, meaning that the lip of the bud twists around through 360? to again be positioned at the top of the flower. Few species in the Anochilus section of Pterygodium are like this.
What the purpose of this action is in the plant’s life, is unclear. Maybe it is a relic of the resupination phenomenon in the genus and Orchid family persisting here in spite of the specific adaptation that finds the lip serving the species best in the up position. All that is achieved is a twisted neck or ovary; still better than a twisted personality (Liltved and Johnson, 2012; Manning, 2007; Le Roux, et al, 2005; iNaturalist).