Kalanchoe thyrsiflora is an accepted name in the RHS database..
http://apps.rhs.org.uk/horticu...
They have two cultivars listed.. 'Bronze Sculpture', accepted, and 'Desert Flame' which is tentatively accepted.
http://apps.rhs.org.uk/rhsplan...
No results were found on the RHS for Kalanchoe luciae, neither were found on Itis. That does not mean K.luciae doesn't exist, they are just not in the database.
SM Growers mention both, closely related.. one has been called the other!
http://www.smgrowers.com/info/...
Those of K. thyrsiflora are more uniform chalky green or white, covered with a thick flour-like coating of wax. The flowers of the two species also differ. Those of K. luciae are not strongly scented and have an urnceolate flower tube with pale-yellow lanceolate corolla lobes. Those of K. thyrsiflora are heavily sweet scented with a cylindric flower tube and brilliant yellow broadly obovate lobes.
Another link to SM Growers on UBC suggests one is the synonym on the other .. which doesn't mean there isn't two species, but one has been called the other!
http://www.smgrowers.com/produ...
It seems there is two species, now all you need to do is decide which yours is.
First check out the Plant list!
The Plant List includes 305 scientific plant names of species rank for the genus Kalanchoe. Of these 73 are accepted species names.
http://www.theplantlist.org/br...
