I've been quite confused about the different types of Tibouchina for awhile now and the more I read, the more confused I get. The two plants I currently have were tagged with the same name (T. grandiflora) when I got them @ 6 or 7 years ago but they are quite different. One has small, soft, pubescent leaves while the other one has small, glossy leaves.
I noticed just now that our database has a listing for
Glory Bush (Pleroma heteromalla) with T. grandiflora as a synonym
* The Catalogue of Life does not show a T. grandiflora but rather this comes up when you type in T. grandiflora:
~ Tibouchina claussenii var. grandiflora Cogn. Infraspecific taxon synonym for Tibouchina claussenii (Naud.)
~ Tibouchina gracilis var. grandiflora Cogn. Infraspecific taxon synonym for Tibouchina gracilis (Bonpl.)
I don't remember where I found this information when googling a few years back so I don't know if any of this is correct but this is descriptive info that I put in a word doc some time ago.
Glory Bush (Pleroma granulosum)
Zone 10 Evergreen Shrub.
Leaves: Shiny, dark green, 4 to 8 inches in length, narrow to elliptic to lanceolate shape. Pubescent below and shiny green on top.
Glory Bush (Pleroma heteromalla)
Zone 10 Evergreen Shrub.
Leaves: Velvety, pubescent, green, rounded; tends to thin out during the winter season.
Spikes of upright flowers.
Princess Flower (Pleroma urvilleanum)
Zone 9b and Zone 10 Evergreen Shrub.
Leaves: Soft, pubescent, velvety.
More cold tolerant than other Tibouchina.