Melastomataceae was documented by European botanists as far back as the 18th century, largely through specimens collected on expeditions to South America and Southeast Asia, but for a long time it stayed mostly in the realm of herbaria and botanical illustration rather than the garden.
Victorian glasshouses and the first ornamental interest
That changed with the Victorian enthusiasm for exotic glasshouse plants in the 19th century. Genera with dramatic flowers or foliage — Medinilla in particular, with its hanging clusters of pink bracts and flowers — were prized additions to the heated conservatories of wealthy collectors in Europe. Medinilla magnifica specifically became something of a status plant, difficult enough to grow well that success with it was a mark of horticultural skill.
Tibouchina's rise came later and more gradually, tied closely to the spread of warm-climate ornamental gardening in the 20th century. As cities in California, Australia, and parts of the Mediterranean climate world built out their public and private garden traditions, Tibouchina's combination of large purple flowers, manageable size, and reasonable drought tolerance made it an easy sell for landscape use — and it's stayed a staple of warm-climate gardening ever since.
Where the family stands now
Today only a small slice of Melastomataceae's roughly 5,000 species is in cultivation at all — Tibouchina, Medinilla, and a handful of others account for the vast majority of what's commercially available, while genera like Bertolonia, Sonerila, and Dissotis remain mostly the territory of specialist and botanical garden collections. That gap between the family's total diversity and what's actually available in a garden center is a big part of why a site like this one exists — there's a lot more here than the plants most people have actually met.