Why Melastome Leaves Change Color the Way They Do

Several genera on this site are grown specifically for foliage color rather than flowers — Bertolonia's iridescent leaf patterns being the clearest example. But color and pattern show up across the wider family too, from the reddish undersides common in Melastoma malabathricum to the deep bronze new growth seen in various tropical species. The mechanisms behind these effects vary more than a casual glance suggests.

Pigment-based color

The most familiar mechanism is pigmentation — compounds called anthocyanins, present in varying concentrations across plant tissue, produce red, purple, and burgundy tones. These pigments aren't purely decorative from the plant's perspective; research links anthocyanin production to plant responses under environmental stress, including intense light and temperature extremes, suggesting a genuine protective function rather than just an aesthetic side effect.

Structural color

A separate mechanism, seen in Bertolonia and a handful of other shade-forest plants across various families, involves physical leaf structure rather than pigment at all — microscopic air layers beneath the leaf surface scatter light in a way that produces an iridescent or metallic sheen. This is a completely different phenomenon from pigment-based color, even though the visual effect can look superficially similar.

Not every colorful leaf is telling the same story — some are showing you a pigment, and some are showing you a physical structure scattering light in an unusual way.

Why it matters for growers

Understanding which mechanism is producing a given plant's color has practical implications. Pigment-based color, tied partly to light exposure and stress response, can shift noticeably with changes in light intensity — a plant grown in brighter conditions may develop deeper color than the same plant grown in shade. Structural color is comparatively more stable regardless of light changes, since it doesn't depend on pigment concentration in the same way.

For the genus where this effect is most dramatic, see our profile on Bertolonia, the jewel plants.