What is "cryptanthus"

Cryptanthus is a genus in the botanical family Bromeliaceae, subfamily Bromelioideae. The genus name is from the Greek “cryptos” (hidden) and “anthos” (flower). This genus has two recognized subgenera: the type subgenus and Hoplocryptanthus Mez. All species of this genus are endemic to Brazil. The common name for any Cryptanthus is "Earth Star".