Each stamp features a photograph of one of these nine species that grows wild in the United States: Cypripedium californicum, Hexalectris spicata, Cypripedium reginae, Spiranthes odorata, Triphora trianthophoros, Platanthera grandiflora, Cyrtopodium polyphyllum, Calopogon tuberosus, and Platanthera leucophaea. Orchids also have common names, with some plants having several different names in popular use.