The Andrea nursery of Boston introduced the first tulip-flowered pelargonium in 1966. The Patricia Andrea deep salmon flowers have 6 to 9 petals that never fully open.
In 2012, the vigorous grower won a RHS Award of Garden Merit.
More varieties are available today, sometime labeled as ‘Popcorn’.
Geraniums The Complete Encyclopedia by Faye Brawner, page 62, print. Schiffer Publishing 2003]
RHS Award of Garden Merit lists, page 76, web: https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals]