Of the roughly 5,000 species in Melastomataceae, only a small number grow outside the tropics and warm subtropics. Rhexia, native to temperate parts of North America, is one of the rare exceptions worth knowing by name precisely because exceptions are so few. The rest of the family, overwhelmingly, is a story of rainforests, cloud forests, and tropical grassland.

An origin story that points south

The current understanding, based on molecular dating studies, places the family's origin in the Neotropics — broadly, tropical Central and South America — sometime in the range of 80 to 90 million years ago, with the bulk of its diversification happening well after that as the family radiated outward. From that starting point, later dispersal events, likely aided by long-distance seed transport, established populations in tropical Africa, Madagascar, and Asia, giving rise to genera like Dissotis and Osbeckia in the Old World.

That deep tropical origin shows up in the family's biology even now. The poricidal anther and buzz-pollination system relies on bee groups that are themselves concentrated in warm climates. Many genera have thin, non-waxy leaves poorly suited to freezing temperatures. And the family's characteristic fruit-and-bird dispersal system works best in habitats with year-round fruiting bird populations — another tropical-leaning trait.

What this means for growers

In practice, this history is exactly why cold tolerance is such a recurring theme on this site. A family that evolved almost entirely within a narrow band of warm, humid latitudes simply hasn't had much evolutionary pressure to develop frost tolerance, which is why so much melastome growing advice outside the tropics revolves around winter protection, container growing, and bringing plants indoors before the first cold snap.

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