Hibiscus rosa-sinensis x '5th Dimension' Malvaceae Kristin Yanker-Hansen, Danville. This is one of the newer hybrids with an 8-inch flower and colors hard to describe. It must be remembered that H. rosa-sinensis is a catch-all name for hybrids that may have several species in their background. All of the hybrids under this species name are tropical in background and don't appreciate low temperatures.