Mandevilla splendens also of 1991.
Leschenaultia biloba of 1992, the only time a specie of this genus is mentioned on a stamp. It was also shown on an 1990 Austalian stamp as part of a bouquet of flowers, but without mentioning it's name.
Comesperma ericinum is too of 1992. The one and only time a specie of this genus is shown on a stamp.
Nidularium fulgens on the left, and Billbergia nutans on the right from way back in 1971. Nidularium has been shown on Brazilian stamps form 1992. Not this specie but 2 other ones. Billbergia has not been shown elswhere.